DETAILS
of
COMMENTS and RESPONSES

Question # 5001:   What are the goods and bads of being a mechanical engineer?
Please click here to offer your response. Reference Question #5001.
Response 1: The good points and the bad points of anything are based purely on personal preferences. I say that because I don't want you to think that I am attempting to avoid giving you a direct answer. Things that I feel are good aspects of mechanical engineering may seem mundane or uninteresting to you. Things that I feel are challenging may seem like troublesome problems to you.

Rather than attributing either good or bad to any aspect of Mechanical Engineering I will instead, simply point out a few of those aspects and let you make your own evaluation.

I will assume that you are an undergrad and have no design or engineering experience in the workplace. If that is the case then let me outline a possible personality profile of a Mechanical Engineering candidate:

  1. Works well in a team environment.
  2. Has a desire to understand what makes something work.
  3. Enjoys working with math.
  4. Enjoys problem solving.
  5. Enjoys building things.

If you posses those five personality traits it's a safe bet you will enjoy an engineering career in the aerospace industry, automotive industry, petroleum refining industry, chemical industry, power industry, machine design and many more categories of opportunity.

You might elect to work for an engineering consultant. In this case, unless you get pigeon holed into one facet of engineering, you could have the opportunity to work in various industries on a project by project basis. If you want to go into engineering but you're not sure which industry you would like to get involved with, this might be your best opportunity at finding what you do like.

By working for an engineering consultant you may have the opportunity to get involved with various industries as well as various engineering activities. It's actually an excellent way to get your feet wet. You gain a broader experience base by working in the different industries and you interact with many different facets and levels of engineering. You have a distinct opportunity to learn something from each industry that you can carry with you to the next. That experience, if taken advantage of, is invaluable.

There are design and engineering activities that are routinely done in the pharmaceutical industry that can be applied to the petroleum or chemical industry. Conversely, there are things done in the chemical and petroleum industry that can be applied to the pharmaceutical industry. This makes you worth something to a potential employer.

From an earnings standpoint, an entry level Mechanical Engineer might have an annual starting salary of about $40,000.00. That is a mid range of between $35,000.00 and $45,000.00.

There are pressures and problems with any job, and engineering is no different. It's just that for most of us, after the long hours, the endless meetings and the concern for doing it right, the final outcome of a good job is extremely rewarding.

Question # 5002: How can a Mechanical Engineer (Estimation Department) reflect his
engineering knowledge in a Construction Company working in the area of
Petrochemical and Refinery Construction (only) projects?

Please click here to offer your response. Reference Question #5002.
Response 1: Estimators for Mechanical Contractors in the Petroleum Refinery and Petro-Chemical industries generally, but certainly not always, come out of the crafts or from design. The experience of working with the tools or having worked with the detail requirements of design provides an excellant prerequisite to estimating.

Although being a degreed Mechanical Engineer allows you to bring much to the table it does not prepare you to be an estimator. Experience is the only thing that can prepare you to do the job properly. Misinterpretting a drawing, not having the ability to see what isn't on the drawings or simply not knowing what questions to ask can place the company you work for at tremedous risk. Having the ability to do those things comes only from experience.

Not knowing where your experience lies, I would suggest that without craft experience or design experience you might find an entry level job in estimating with a mechanical contractor at a job site location. I say this because routinely the estimating that takes place during the up front bid phase of a project is much more envolved due to time constraints and the potential at-risk situation for the company. Although this would be great experience it would be like by-passing the frying pan and jumping directly into the fire.

Making your introduction into mechanical estimating at a site location has a couple of advantages; you have an opportunity to experience, first hand, the problems, issues and concerns of building a petroleum refinery or chemical plant. You'll be involved in estimating labor & material for field changes, processing RFI's, work with vendors and much more. It is the type of hands-on experience that will serve you well.

If you later have an opportunity to move into a project engineering or project management position you will find this experience invaluable.

Response 2: You are a very lucky young man. Starting off in the estimating department will give you a great background on how things are put together in a mechanical system. You not only learn how much it costs to install a system, you learn how to read and understand P&ID's and Isometric drawings.  You also will learn how a piping system is put together with other the other trades (electrical, insulators, carpenters, iron workers, concrete work, etc.) I hope that you don't think that you will be stuck at that position for the rest of your life. While you are busy learning how to become a good estimator, you also need to learn how to become a scheduler (MS Project or Primavera). While you stick those two tools in your toolbox, you need to start building yourself a three ring binder on all of the things you have learned as you go. Don't be afraid to ask design engineers how or why they design piping/equipment on the drawings that you are working on, most of them will be glad to help you learn their part of the trade. Use your time in the estimating office to start building your own documentation of how you would design a piping system from the ground up. Learn to use AutoCAD  for simple isometric drawings, then build on that skill. I spent many years as a pipefitter, got my mechanical degree, started in estimating, worked my way into project management, got into inspections and finally ended up in design (where I wanted to be in the first place). Be pro-active on learning the things you want to know, ASK! Never stop asking or bugging people with questions.

Question # 5003: When is the piping community going to let those that have PDMS training( like myself) be allowed to work in this area? I really like this program and did well in training at Cadcentre, in Houston, but am not allowed, like others I know, to work in it without 6 months or 1 year EXPERIENCE.
Please click here to offer your response. Reference Question #5003.
Response 1: There are a number of opportunities for new graduates of PDMS training. In obtaining and performing project work an engineering firm as to be cost effective in utilizing their personnel. If every designer or engineer on the project had ten plus years experience their pay rate would make the project cost prohibitive. The activities on a project are therefore balanced with a determination of required experience for each activity. Some activities on a project don't require essential experience. These are entry level positions.

Even without an experience requirement these entry level positions may still require a certain level of education or training in order to perform the basic duties required of those positions. This is where your PDMS training comes in. There is an activity in the design phase of a project that requires the rework of drawings during the development of design. Whether it's piping, P&ID's, structural, E&I, HVAC or architectural there is a continuous stream of changes. In order to make the best use of design personnel the supervisor will assign someone with little or no experience to making these changes. It doesn't necessarily require experience in a particular discipline but it does require knowledge of the CAD system that is being used.

This activity requires that you follow color coded changes, corrections  and comments on prints (mark ups) that were made by a designer or engineer. These changes need to be applied to the drawing file and can be done by a CAD operator with no experience.

There are currently a number of entry level job openings for PDMS CAD operators. Once in a job gain the experience and look for better opportunities. If, after a year or so, you see an opportunity to improve your position make your move.  Whether it's an internal move within the company that you're gaining your experience with or another company altogether, wait for the opportunity while gaining experience.

Response 2: The piping community does not disallow people with a PDMS course experience of working within the discipline. What it will do however is to prefer their designers / engineers to have more experience than the writer of Q#5003. I have more than 25 years piping experience covering pharmacutical, petrochem and O&G work, I have worked onsites, in offices and offshore (British and Norwegian sectors of North Sea) and also worked in a desert based location in Libya. I have practiced PDMS for 2 years and PDS for 7 years, and all of this was preceded by a 4 year drawing office apprenticeship which involved a ''day-release'' scheme to allow me to complete my college examinations.
It's up to the company hiring in to decide what they want, but with so many of the recent projects recently being classed as ''fast-track'', the last thing you need in a design house is someone with no piping experience other than doing a piping orientated CAD course.

I read that the response #1 ''if every designer / engineer had 10 years+ experience then the pay rate would make the project cost prohibitive'', I understand that way of thinking but I would have to ask the writer, who is to train the boy or girl that comes into the office with no experience other than a training course ?, and note that it is a course you do in PDMS, there is no exam and the certificate you receive at the end is simply an attendance certificate ! You could end up with oft quoted, '' office full of re-trained taxi-drivers''.

In short I do not think that a PDMS course certificate is any qualification to
allow you near a 3D model.

Cheers ARu.

Response 3: hi,piping people it is my first contribution here.I'm a piping designer for 12 years now,31 years old,practicing pdms since 3000 hours.Actually workin for a big off-shore company on silicon graphics good o2 stations under unix network.I f i can give an advice if you are just entering in the pdms world.Find a little company which is develloping or workin with pdms,here for you the advantage will be to work with all the modules(structure,piping,draft,...).That's  what i did 3 years ago,i had the choice beetween a big engineering trust who wanted to form me on PDS ,and the other one was a little french company with PDMS.I analyze and choose pdms.3 days of formation(ha ha ha),i join a team after 4 days and starting with equipments,easy guyz,after structure beams,panel plates a little more harder,after start the piping(all my team has help me to progress).And at the end piping,draft and review(animation sequences).To resume i have touch all in that program now i'm abble to built alone an entire project from a to z (excluding admin it is another level).At my second project i built 300 pipes "no data inconsticencies hey hey",we were two guyz on it,too much crazy of my boss to put trust in two young guyz for a Total fina,exxon project,but aniway at the end we did it well!!!.Now note that in big companies you are a piping designer in a task force team and that's all,you just start to put the equipments and nozzle somes basic ladders and plateforms and after it is the structure team wich is continuing in detail structure ,etc etc...Your job is piping!
Hope it has help you cheers :)

Response 4: Hello, I want to study PDMS COURSE in E&I PLS. guide me.
With regards, K. Aravzhi
aravazhik@hotmail.com

Response 5: It's a good response from all of you ,but one thing you fail to realise is that do the little companies want to even give the young expereince PDMS designers a change.they are all in the market to maximise profit and would want to risk their jobs with their client thereby not giving the young ones a chance to make a career.If the second writer wasn't given the opportunity would he have become what he is today? We should rethink and has the moderator has stated the young ones should be employed and allowed to do little jobs with the software before progressing to the more tasking ones. Thanks, Preye Apere

 

Question #5004: I am taking a physics course in highschool. For a project I am doing, I need a mechanical engineer to answer a few questions.
1. In college what were the courses you took to become an mechanical engineer?
2. What were some highschool courses that were required for engineering courses in college, and what were some highschool courses that you felt really prepared you for your work?
3. After gradutation from college was it easy or hard to find work, how did you finally get the job?
4. What parts of your job did you enjoy most then?
5. What parts do you enjoy most now?
6. What is your yearly salary?
7. What are the duties you have?
8. Please describe a typical day at work
9. Is there room for one to advance as mechanical engineer?
10. How much did your college education cost, where did you go to college?

Please click here to offer your response. Reference Question #5004.
Response 1: Following are the above repeated questions and their corresponding response in capitals:
1. In college what were the courses you took to become an mechanical engineer?
THERMODYNAMICS, HEAT TRANSFER, STATICS, DYNAMICS, CONTROLS, FLUID MECHANICS, CONTROLS, COMPUTER SCIENCE, STRENGTH OF MATERIALS, PHYSICS, CHEMISTRY, LOTS OF MATH.
2. What were some highschool courses that were required for engineering courses in college, and what were some highschool courses that you felt really prepared you for your work?
TAKE AS MUCH MATH, CHEMISTRY, AND PHYSICS AS YOU CAN GET.
3. After gradutation from college was it easy or hard to find work, how did you finally get the job?
I HAD FIVE JOB OFFERS BEFORE I GRADUATED. I STARTED THE MONDAY AFTER GRADUATION.
4. What parts of your job did you enjoy most then?
UNDERSTANDING WHAT THE TECHNICAL PROBLEM WAS THAT I HAD TO SOLVE AND DEVELOPING THE SOLUTION.
5. What parts do you enjoy most now?
PRETTY MUCH THE SAME. I ENJOY THE DESIGN SIDE MORE THAN THE MAINTENANCE SIDE OF ENGINEERING WORK.
6. What is your yearly salary?
A TYPICAL SALARY FOR A MECHANICAL ENGINEER WOULD BE APPROXIMATELY $50,000.00 PER YEAR. THIS IS STATISTICAL AND CAN VARY DEPENDING ON LOCATION, COMPANY AND SPECIALTY, IF ANY.
7. What are the duties you have?
IN THE JOB I HAVE NOW, I AM A MECHANICAL ENGINEERING RESOURCE TO OUR CORPORATE PROJECT MANAGERS WHO ARE DELIVERING BUILDINGS FOR OUR COMPANY. THESE BUILDINGS MAY BE OFFICE BUILDINGS, OR PROCESSING BUILDINGS FOR OUR PRODUCTS. I WORK WITH OUTSIDE ENGINEERING FIRMS, EQUIPMENT VENDORS, AND CONTRACTORS TO MAKE SURE THAT OUR COMPANY GETS WHAT WE NEED TO MEET OUR OBJECTIVES.
8. Please describe a typical day at work.
I COME IN, CHECK MY EMAIL AND VOICE MAIL, REVIEW DOCUMENTS GENERATED BY THE ENGINEERING FIRMS WE WORK WITH, DRAWINGS, SPECIFICATIONS, AND MAKE SURE THAT THEY COMPLY WITH THE INTENT OF THE DESIGN, GOOD ENGINEERING PRACTICES, AND OUR COMPANIE'S STANDARDS. I WORK WITH THEM TO DEVELOP THE DESIGNS AND MAKE SURE THAT THEY ARE MAINTAINABLE.
9. Is there room for one to advance as mechanical engineer?
IN THE COMPANY I WORK FOR THERE IS QUITE A BIT OF ROOM FOR ADVANCEMENT ON WHAT IS CALLED THE "TECHNICAL LADDER".  HOWEVER, THERE IS MORE ROOM FOR ADVANCEMENT IF YOU MOVE OUTSIDE OF ENGINEERING AND MOVE UP THE "ADMINISTRATIVE LADDER".
10. How much did your college education cost, where did you go to
college?
I AM NOT REALLY SURE, I WENT TO PURDUE (A STATE SCHOOL). I WENT THROUGH A CO-OP PROGRAM WHICH ALTERNATES WORK AND SCHOOL WITH A COMPANY THAT NEEDS ENGINEERS. I HIGHLY RECOMMEND THIS APPROACH BECAUSE IT HELPS PAY FOR SCHOOL AND GET YOU VALUABLE WORK EXPERIENCE IN YOUR FIELD.

Question #5005: Back a few years ago there was a rash of counterfit ANSI flanges found in the US as well as below or off spec stainless steel fittings from the Pacific Rim. My company, like many others, made it our policy to not purchase these materials from suppliers (manufacturers located) in these regions.
Does anyone know of any current information on this topic? If so I'd appreciate your help.

Please click here to offer your response. Reference Question #5005.
Response 1: The issue I believe you are referring to was reported in the October 12, 1992 issue of the Engineering News Record. It was triggered by a contractor that was prefabricating pipe for a refinery project. They found a crack in a 14" flange and turned it over to the National Board of Boiler and Pressure Vessel Inspectors.

As it turned out, after a year long investigation that included two trips to China, the flange, which had been manufactured in China, was one of a number of flanges and fittings that, through full metallurgical tests, were determined to be dangerously defective and falsley marked as complying with ASTM & ANSI code requirements.

That issue was investigated, the manufacturer identified, notifications issued and the book closed. To date, this writer has heard of no other such issues pertaining to inferior flanges and fittings.
Response 2: Protect yourself or your company by requiring the chemical reports on flanges.   ASME Code requires all documentation.  The Chinese fabricators
tried to sneak in flange parts which did not meet the ASME required material properties on forging.

Bharat V. Makadia, P.E.

Response 3: Over the past two years I have found three 6” 150# weld neck flanges with cracks in them 2 leaked on hydro and one found by x-ray. Also a 4” 150# weld neck flange found during welding process. Note: all four were from India three were known to have micro stamped on them

Response 4: Hi, I am a Sales Engineer working in a company distributing pipes, flanges and fittings for Oil and Gas Industry. I too have experienced getting defects slip on flanges from China. It is a worrying trend in our industry that these people are trying to make more money by compromising quality in their production of flanges. I think it would be best that we disclose these  irresponsible manufacturers and inform them to the industry so that they may not supply their goods to others. Attach are some photos that we took when we discovered the cracks after hot dip galvanizing. If the flanges were not hot dipped galvanized we may not even discovered the cracks as the cracks were covered by rust protective black paint.

 If you guys out there have the same mishap of buying defect flanges or piping components from irresponsible manufacturers please do share with me. (henry@pantechcorp.com)

 Thanks.

 

Question #5006: We are having a problem with short life span (less than 5 years) of copper tubing when used for water supply in a large manufacturing building. We are aware that excessive velocity can cause this problem. Is anyone else suffering from short life span when using copper tubing for water supply and what else could be causing this problem?

  1. Explanation of failure.

    The tubing "fails" at elbows, in the middle of straight runs, seemingly at just random locations.

  2. What type of water is it?

    Well water; potable & process cold water; hot & cold soft water

  3. Operating & design pressure?

    60 - 75#

  4. Operating and design temperature?

    Cold water 55-65 F, hot water 75 - 140 F

  5. Size and wall thickness of tubing?

    Up to to 6'' in size; seamless copper tubing ,type L, per ASTM B88, UNS No. C 12200 and Federal Specification WW-T-799-F

  6. Velocity of water at failure points?

    < 5 fps cold water systems; < 4 fps hot water systems

  7. If this is a distribution system is the problem throughout or localized?

    Located throughout the system

  8. Does the system experience water hammer?

    No

  9. Does the system supply operating equipment or static equipment like drinking fountains?

    Operating equipment

  10. If the tubing supplies operating equipment does the feed to the equipment cycle abruptly (on/off)?

    No

  11. Does the equipment vibrate?
    No

Priority of failures:

1) Hot soft potable & process water (most prone to failure)

2) Cold soft potable & process water

3) Hot hard potable & process water

4) Cold hard potable & process water (least prone to failure)

WATER TREATMENT HISTORY:

BASE 1
Well water, 80 ppm CO2; 7.0 PH; chlorine added at 0.5ppm

BASE 2
Added sodium silicate to rid CO2 (did not help in controlling CO2)

BASE 3
Injecting caustic to adjust pH to range 8.2 - 8.4, C02 gone; but iron foamed up, softened and plugged nozzles.

PRESENT
Injecting caustic to PH range of 7.6 - 7.8 CO2 = 28ppm; foaming not a problem, presently observing system.

Response 1: Has the system been properly isolated from any possible electrolysis (dielectric unions)? In the past I have also heard of problems with copper pipes if located near a high power line. The only solution to the problem was to install sacrificial anodes along the line. The anodes needed to be changed every 3 years.

This is the only thing I can think of without actually seeing the project and the pipes.

Response 2: Have you checked the chemical composition of the water supply ? Even potable water supplies can have high levels of naturally occuring corrosives. Copper or Zinc minerals in the surrounding soil usually will have attendant acidic properties that can cause the sort of corrosion that you are describing. A greenish or blueish residue (which is actually the corroded copper) in sinks and toilets is usually a telltale sign. This condition is most often found in Well Water supplied systems. The solution is a water treatment system.
Please click here to offer your response. Reference Question #5006.
Response 3:

Question #5007: Lisa writes -I am looking for a few good books on pipe fabrication, estimating & bidding, and or petrochemical piping - to be used in the petrochemical refinery
business. Could anyone recommend some good ones for me...

Please click here to offer your response. Reference Question #5007.
Response 1: Visit the Piping News Bookshelf Page. There are seven categories containing a selection of 86 books. Within the content of these books is the subject matter you are looking for. These books discuss pipe fabrication, estimating, bidding as well as the design and engineering of petro-chemical facilities. The books posted on this site are books we are recommending. We are primarily concerned with definition of content. Not so much as to whether or not the book is very broad in its content (although that is a factor) but how well it defines and articulates what it does cover. If a book discusses a subject we expect it to do so in a well defined manner.  

Response 2: Contact me (m.warren@charter.net) and I can point you in the right direction

Question #5008: How does a steam trap function?
Please click here to offer your response. Reference Question #5008.
Response 1: Go to http://www.pipingnews.com/memberpipingne/steam_traps.htm, your question should be answered. This is a design article that covers the basics of steam. Within this article is a section on steam traps, which the above link will take you to. It will explain that there are basically three types of steam traps: Thermodynamic, Thermostatic and Mechanical. The Thermodynamic type trap includes the orifice type and the disc type traps. The Thermostatic type trap includes the balanced pressure and bimetallic type traps. The Mechanical type trap includes the inverted bucket and float & thermostatic type traps.
The article goes on to describe how each type of trap operates and how they are normally used.

Response 2: Check out http://www.steamlink.com It has plenty of sites to visit to answer your questions.

Response 3: Steam traps fall into 3 major categories:
        (1)  Thermostatic -  these steam traps sense the temperature differential between hot condensate and cooler condensate.  As the condensate warms up, the
              trap  closes to prevent the escape of live steam.  These traps do not respond to the amount of condensate in the system - only the temperature.  They
              are mainly found in residential and commercial applications.  Typical traps include bimetallic traps, corrugated bellows traps.


        (2)  Mechanical -  these traps respond to the fluctuating condensate load.  As condensate enters the trap, the trap element lifts and allows the condensate
              to escape.  Some mechanical steam traps incorporate a thermostatic element in them to assist in venting out gases and air.  These traps are very popular
              in industrial applications.  Typical traps include Float & Thermostatic steam traps, inverted bucket traps.


        (3)  Thermodynamic  -  These traps operate according to Bernoulli's Theorem.  As the velocity of the steam increases, the corresponding pressure decreases
              and closes the trap.  These traps are excellent where freezing is possible.  Typical traps include disc traps and impulse traps.

Question #5009: Why do we provide 3mm steel rod on sleepers/piping resting supports? Why can't we directly lay pipes on sleepers or steel structure?
Please click here to offer your response. Reference Question #5009.
Response 1: Could you provide a description of how the 3mm rod is used in supporting pipe at a sleeper? This seems a little unusual. However, until your description regarding use of the 3mm rod is received and posted I will provide the following support information:
A sleeper refers to an isolated and low lying pipe support. The term sleeper, in relation to piping requirements, actually comes from the use of timbers laid horizontally on the ground as cribbing to support pipe close to the ground on a temporary basis. On a more permanent basis, and in some cases to comply with code, sleepers are constructed of concrete and steel.
In supporting pipe there is really no difference between supporting pipe on a sleeper and supporting pipe in a pipe rack, or pipe arbor. The same criteria that forms the basis for the determination and design of a support in a pipe rack will be the same criteria used to determine the proper support on a sleeper. Without knowing the particulars with regard to the use of the 3mm rod your question cannot really be answered.

Response 2: The main reasons for providing the 3mm dia. rod for pipe supports are as follows:

1)The rod ensures a point (or line) contact between the pipe (or the pipe shoe) and the supporting member viz. sleeper or steel. This helps in eliminating or minimising the effect of friction at the support. An area contact (as to be expected when the pipe shoe is made to directly rest on the supporting member will cause friction to come into the picture, which
can increase the net load at the terminal anchor / equipment nozzle.
2) Since piping on sleepers or pipe racks are usually in the open, they are naturally exposed to the elements. Thus, when rain water collects underneath a pipe support (especially under the shoe), it is a potential corrosion initiating point. Providing a rod in between shifts the corrosion to the rod from the pipe surface and this rod can be easily replaced over a period of
time when compared to the more expensive pipe which can also result in the loss of plant production due to a necessary shutdown for replacement.

Response 3: Rod between pipe shoe and sleeper results in point/line contact which in turn reduces the friction in axial direction. This is the only main reason of providing rod. Other could be, it results in steel to steel contact otherwise it would be steel to concrete contact in case of sleeper....
Response 4: People are getting way too deep into this friction thing. Since the onslot of computer stress programs, people are acting like pipe slides all over the place. There is intial friction, theoretically, but this is just that, theoretical. unless you are getting close to critical stress, don't read too much into friction unless you are dealing with big heavy pipe.
Response 5: I work in a Refinery near the Gulf and laying any piping directly on a sleeper or steel structure will lead to an area of corrosion that will come back to haunt you over time. The same is true for the 3mm rod. The best thing to do is use what is called a pipe shoe that is welded to the pipe and rests on the support. Imagine a wide flange beam cut in half thru the web that is about 4" tall. The flange of the wide flange is what rests on the support.

Question #5010: I have seen the letters "NBS" stated in a particular specification under the
"Codes & Standards" section. Does such an organization exist and what do
the letters represent?

Please click here to offer your response. Reference Question #5010
Response 1: What "Codes & Standards" are you referring to? And what is the context in which this acronym is used?
Response 2: Anand Chordia-India: Are u sure that u have seen this under "codes & standard"?
In my opinion, NBS refers to "Nominal Bore Size" 

Question #5011: What has happened to all of the petrochem/refinery piping jobs?
Please click here to offer your response. Reference Question #5011
Response 1: They are not in Baton Rouge. It is slow here. FB&D and Jacobs are the only places with a little work, but you have to be someone's son-in-law to get a job.
Happy Hunting,
Frank Boyd

Response 2: I don't know. It's been slow here in Western Australia as well. There are several rumours of projects starting, but it is only rumours at the moment. If you do happen to find out please let me know.
Andy Woodford
Perth, Australia.

Response 3: Slow in Michigan.
Thomas
Response 4: Slowest that I have seen it here in Houston since 1982-1986.
Richard, Houston, Tx.

Response 5: Also the slowest I've seen in years.Heard there is lots of piping design work in the Netherlands. Any truth to this rumor? Any contact names or numbers?
Response 6: Been slow here in Alberta Canada to, but with freeze up just around the corner all HELL is going to break loose. I manage a NDT inspection offfice and last two weeks lots of requests for Quotes starting to roll in. Anybody want to visit i'm at glynnxray1@aol.com
Response 7: Anand,India- I can not say that it is totally lean or dry but not very encouraging too. Some projects are coming up but either they are too small or related to ETP.
Response 8: Yall have said it all ! I just came from a semiconductor job in China and they shut that job down with a good 1 1/2 years to go. Now i'm home and there's no work here in Dallas either . On a good note I've heard that this recent drop should reverse it self at the start of the next quarter in Sept. Recent drops in the market are mostly to blame companies are laying off thier own to boost the falling profit margins and have haulted most of the constuction since building cost really affects there bottom line.
Response 9: I hear that there some of the large A&E power Engineering Co. are coming back up and looking for pipers in ACad 14 & 2001,2.     Don't want to name anyone here.
Response 10: you only need 1 job fellows... DAVIN
Response 11: Slow to dead in Jersey & surrounding N.Y., Phila area. Some small jobs around. Most big engineering houses have been cutting their staff to the bone. Some are forcing voluntary leave of absent. Job shops are not advertising. Normally we are out of phase with the rest of the economy. But is this phase of something to come to the economy or something that has been? Maybe it's time to get a job as a politician. There the only one's employed.
NJROK
Response 12: Just got done doing a job for Tech-nip USA in Cordova, IL. Friends there have a very bleak outlook on the sector as whole. Was rumored Tech-Nip may even close US operations to concentrate more in Latin America.
Kevin Conklin

Response 13: I have been a piping designer for 30 years and have never seen the market so low. Reminds me of Houston in the early 80's. Rod
Response 14: All of our jobs have been exported to Eastern Europe, The Philippines and India.
Brian
Response 15: In talking to the heads of different departments, about sending jobs to India. if they get 25% of the job done right, field engineering can fix the rest of it and the Corp. can still make a "lot" of money on the job, Approx wage  per Hr. = one -1.00 per. hr. total package.  So how do we in the USA beat that ??

Question #5012: Does anyone have pressure temperature ratings for backing flanges with angle face rings? I am afraid of misapplying the use of backing flanges or Van Stone type flanges.
Please click here to offer your response. Reference Question #5012
Response 1: If the backing flanges, aka: lap joint flanges, lapped flanges and van stone flanges, comply with  ASME B16.5 requirements there should be no concern. These types of flanges do not have face rings. Any facing would be done to the gasket sealing surface which, in this case, would be the flared portion of a stub-end. If the pressure/temperature charts in B16.5 are used for the respective flange material of construction then the proper flange rating can be determined.
Response 2: There is NOT any pressure/temp. chart for Van-Stone (lap joint) type flanges, which use angle for backing ring as the flange.  The ASME Code prohibits the use on non-standard flanges unless they meet the B16.5 requirements.   You will have to design each pipe diameter flange, one at a time, to come up with the rating.  You need to use, Appendix II as the design basis.   Don't forget that the gasket seating stress play a big part in this. Let me know if you need any help.  I do consulting.

Bharat V. Makadia, P.E. 
(503) 806-2782 USA
Response 3:
There are currently no pressure and or temperature ratings for van stone flanges. In my experience you will see company's trying to make use of material on hand use slip on flanges, not recommended by me but it did work.
Kevin Conklin

Question #5013: For a university in the Netherlands, I have to carry out a technical research (to graduate for mechanical engineer) concerning the present use of oil and gas wells and the relation with small diameter pipelines (4 to 6-inch)in the U.S. Upstream Oil and Gas Producing sector for flowlines, gathering lines and water injection lines. My target areas are Texas, Louisiana, California and Alaska.
I hope you can furnish me with the right (needed) answers for the following questions:
- Actually, how is the upstream oil and gas industry exactly divided into pipelines from the well to the battery for oil, gas and water fluids.
My following 7 questions are concerning the target areas Texas, Louisiana, California and Alaska.
- An indication of the range of used wellhead pressures and temperatures for 4 and 6-inch flowlines,gathering lines and water injection lines.

- An indication of 4 and 6-inch flowlines and  gathering lines which flow with a maximum operating (wellhead) pressure of 6,0 MPa and maximum 65 C   degrees.
- An indication of 4 and 6-inch water injection lines  which flow with a maximum operating (wellhead) pressure of 8,0 MPa and maximum 65 C degrees.
- Total length of flowlines, gathering lines and water injection lines for the 4 and 6-inch.
- Indication of lengths of the 4 and 6-inch flowlines, gathering lines and water injection
lines which are above or under the ground and why.

- What is the (normal) length of a flowline, gathering line and water injection line and on which factors does it depends.
- Temperature (climate) range in which the flowlines,  gathering lines and water injection lines have to operate and what effects does it have on the   operation.
- Which type of materials are used for the flowlines, gathering lines and water injection lines and the  reason why.
- What’s the average life span of flowlines,  gathering lines and water injection lines, made of steel, fiberglass, and on what factors does it   depend.
- What are the estimated total costs (material, installation, etc.) to install 4 and 6-inch flowlines, gathering lines and water injection lines and the yearly estimated costs for maintenance.
- What steps and regulations do you have to followt to get an approval for a flowline, gathering line and water injection line.

Please post any additional information about flowlines, gathering lines and water injection lines that you feel could be usefull for my research.

Thank you, Erik
Please click here to offer your response. Reference Question #5013
Response 1:


Question #5014: Does anyone know of any industry standards for coke oven gas with a high hydrogen percentage (60%)?

Please click here to offer your response. Reference Question #5014
Response 1:

Question #5015: In a refinery plant ,which is preferrable location for air coolers : top of piperack or top of technical structure?
Please click here to offer your response. Reference Question #5015
Response 1: Depending on the overall layout and design scheme, and not being sure what is meant by "technical structure", the pipe rack would be your better location. That location should allow for unobstructed air flow in addition to being remote and inaccessible from normal personnel activities.
Response 2: From Anand-India: It can be either on Pipe rack or technical structure. Generally, in refinery, Pipe rack is one of the heaviest sturcure carrying piping loads. Apart from the facts given in response 1 like unobstructed airflow,remote and free from man movement other reason is the dead wt. of the air coolers can easily be taken by the Pipe rack which is one of the heaviest structure and we get ample flexibility as regards to location and providing platforms for maintainence etc. without increasing the size of the sturcture (much).
Moreover, aircoolers are always in pair,normally 2 to 20 or more. These many no.of air coolers can be easily accomodated along the pipe rack without adding sturcute. If no. of air coolers are say 2 and routing scheme permits then we can put them on technical structue too.

Question #5016: Which location is widely used to locate pumps in a A) Refinery, B)Petrochemical plant & why i.e. below piperack OR along piperack (and outside it) ?
Please click here to offer your response. Reference Question #5016
Response 1:The first step in creating a layout for your facility is to develop a routing diagram. This provides an overview of the entire system and allows you to visualize the relationship of the equipment based on flow patterns and sequence of operation. Pumps, when overall design considerations allows them to be located in close proximity to a pipe rack, should be located outside the framework of the piperack. Depending on the type and size of the facility, the piperack will generally run through the middle of the facility with flow moving in and out both sides of the rack.
The area below the piperack remains clear and serves as an access corridor. With the pumps facing away from the piperack it allows maintenance clear and easy access when pulling their carts or a picker up to any of the pumps to perform maintenence. 

Question #5017: What are the design parameters for location of flare towers in a process plant, taking into account factors
such as predominant wind direction, sources of gas leaks, location of process units, utility units etc?

Please click here to offer your response. Reference Question #5017
Response 1:

Question #5018: Does anyone have any information (Excel Spreadsheet mounted) on Piping installation manhours, pipe - valve - fitting densities profiles or any of the like for estimation purposes?
Please click here to offer your response. Reference Question #5018
Response 1: Yes, Cherne Mechanical of Minnesota has a unbelievable detailed spreadsheet estimating everything you can possibly think of in the way of
B31.3 installations. I use to work with an engineer who worked for Cherne and he said that was the only thing that he forgot to take before he left there. It was built from the data inputted from many refinery jobs that Cherne had done over the years. Try contacting someone who works for Cherne (other than Human Resources) and see if you have any luck.

I use the John S. Page manuals for estimating which turned out very accurate for the majority of the project work that we did at Refineries. I also use it to teach estimating, very user friendly and easy on the pocket book.

Ashland or Marathon used Primavera Scheduling and Richardson's Estimating manuals (Richardson was definitely not user friendly). The best estimating spread sheet is the one that you develop yourself with the recorded data of actual Projects that you gather. Experience is the best teacher, but it is always nice to have a mentor to lean on.
Response 2:
estimation requires experience and every good estimator will have stored data. There are no magic formulas for estimation otherwise all bids would look the same. There are many considerations to take in account i.e. labor contracts, man power, cold weather impact, etc.. This is only scratching the surface. To be a good estimator and set yourself apart you must first understand and learn the trade, or be allowed to make the mistakes with a deep pocketed company. You will see a lot of contractors on there schedule of values quote M. C. A.  rates but they would never dare try to bid competitively with those rates.
Kevin Conklin

Question #5019: I have a question in regards to commissioning a fairly long underground steam line. The task at hand is as follows:

* steam line length 3500 meters
* steam line diameter 225 millimeters
* steam temperature approx. 303.4C
* steam pressure approx. 9000 kpa

Our situation is that we produce 80% dry steam which is then ran through a separator and then fed into the pipeline. Does anyone have any suggestions for safely commissioning this pipeline to keep water hammer at a minimum.

Please click here to offer your response. Reference Question #5019
Response 1: You are asking an engineering question expecting cookie cutter answer like a Sears Catalog.  They would not need engineers if it was the case. Answer to your problem is not a cook book.  Wonder how do you get this kind of complex job without qualifications!!

What ever happened to the good old in-house engineering department or using experienced consultants!

Anyway, you need to follow the ASME code to make sure that the code intent is satisfied.   Otherwise you are asking for lot of headaches and law suit.

Response 2: Call a company like Spirax Sarco. They would analize your system and give you solutions.


Question #5020: What is the difference between true north and plant north?
Please click here to offer your response. Reference Question #5020
Response 1: A plant North is used much like a fictitious elevation ... for convenience. If a plant is going to be constructed at a nominal elevation of 798 feet above sea level a bench mark will usually be established to create a fictitious elevation that is much easier to work with. Whereas 0'-0" = 798'-0" allowing the use of less cumberson numbers in calculations and on drawings. The same thinking applies to the use of Plant North.

As you probably know there is a true North and a magnetic North. The variation between the two changes on a gradual, continuing basis. Plant North is established off of true North when a plant cannot be constructed, because of building constraints, on a true North/South line. This allows the designer to layout the plant squarely on the drawings rather than skew the layout at an angle. The deviation is sometimes indicated on the drawing by showing both the true North and the plant North with deviation indicated. In other cases the deviation is discussed in the project design basis and only the plant North is shown on the drawings.

Response 2: This note is prepared to explain the significance of GN (Geographical North) and PN (Plant North).

Ask anybody around you to tell you the Geographical North. Each one will indicate some direction but nobody will be able to confidently say that the compass will also show the same direction. Given a compass, each one will be able to mark the Geographical North.

Same way, none of the people working at construction site (hundreds of them) will be able to proceed with the work by referring to Geographical North.

Now ask the people around you to face perpendicular to a specific wall. They will be able to do it. But again, some of them may face in one direction and others in direction 1800 opposite. In this case, you defined the North-South direction (i.e. the wall) and asked them to face East or West (You did not give them correct directions)

Now tell the people which end of the wall is to be considered as North end and which one as South end. Then ask them to face towards East.  All of them will face in one direction only. In this case, you defined the Plant North and could ensure orientation of all the people in the direction desired by you.

With the help of a compass, you can tell the angle between the Geographical North and the direction of the wall i.e. Plant North.

That is why it is essential to mark Geographical North and Plant North on the Overall Plot Plan (Which is also called as Site Location Plan or Plant Layout.) and the relative angle between these two.

Geographical North is always available on the contour map for the land acquired by Customer. If it is not, it can be marked by using compass and the permanent bench mark.

Plant North can be any real and permanent line, say wall of a process block or any building.

Dilip Deshpande

Question #5021: What is "Seal Pan" in Vertical Towers? What is the importance of the same?
Please click here to offer your response. Reference Question #5021
Response 1: A seal-pan is a pan that contains condensate from the condensed vapor that rises up through the tower. It sets at the base of the downcomer where the bottom of the downcomer extends below the liquid level in the seal pan. This effectively prevents vapors from by-passing the sieve tray while allowing liquid from the upper trays to flow down the downcomer located at each tray.

Question #5022: From MLK, Baroda-India: What is the economical option as regards to fabrication and material- HDPE or C.S. for a given size?
Please click here to offer your response. Reference Question #5022
Response 1:
You ask a hard question in a short sentence.  HDPE is of course very expensive in comparison to CS and also hard to work with as far as the
fabrication process.

What are you trying to fabricate?  There may be another material option as an alternate to HDPE.

I do consulting in the area of piping, pressure vessels, heat exchangers and tanks.   I have extensive design/fabrication type background in the area of ASME, API & TEMA type equipment.

Let me know if you need my help.  Good luck.  

Bharat V. Makadia, PE (Oregon, USA)

Question #5023: Amit Biniwale-Baroda,India:What is the meaning of term steam out ?
Please click here to offer your response. Reference Question #5023
Response 1:
The term "steam-out" refers to the process of using steam to clean out a piping system. Some piping systems handle fluids that have a tendency to build up on the inside of pipe, plug up valves and compromise instruments. In some cases a chemical flush is used, in some cases steam is used, and in other cases a combination of steam and chemicals are used to clean out the piping system. The combination of heat and velocity through the piping is what makes the steam-out process such a useful means of cleaning out a system. It alleviates, or at least reduces the need to handle chemicals, both from a personnel standpoint and from a waste standpoint.

Question #5024: From Vipul Desai, Baroda- India. "Can anybody recommend me any piping course conducted in India except I.I.T.Powai (Bombay) ?" I.I.T. Powai course in my opinion is bull shit!
Please click here to offer your response. Reference Question #5024
Response 1: Sorry! Vipul, IIT course is not bull.... It is a very structured course. Prof. Moharir is doing a great job. One can only teach so much in a span of 30 days. If you want a more detailed course try contacting MIT-Pune.
Response 2: In  India following institutes are conducting piping courses. you can visit their websites & find out more details..
 

bulletMIT, Pune, India
bulletVIT, Pune , India
bulletTrinity Institute, Pune, India
bulletElixir institute, Thane, India
bulletSuvidya Institute, Mumbai, India

Best Regards

Shekhar Sali

 

Question #5025: What is water hammer?
Please click here to offer your response. Reference Question #5025
Response 1: Water hammer, also known as hydraulic transients, are actually surge waves that occur in water, steam and condensate lines. They can also occur in gaseous pipelines that have a tendency to accumulate condensate.

In liquid lines they can be the result of suddenly closing a valve, or the starting or stopping of a pump. In steam lines it can be caused by the accumulation of condensate. In condensate lines it is the result of poor line sizing that does not accomodate the two phase flow requirement required in steam condensate piping, or from system upsets.

What occurs in a liquid line when a pump shuts down, or a valve closes too quickly is that the kinetic energy is changed to a pressure energy in the form of a surge wave. This surge wave moves back up the pipeline from the point of impact creating the water hammer effect.

In a steam line or condensate line, and to some extent gaseous pipelines, the result is the same but the cause is different. Low pressure steam normally flows at a velocity of around 6000 ft/min. If condensate is allowed to accumulate in a steam line it could eventually close off the annular cross section of the pipe. As it accumulates, the velocity of the steam moving across this buildup of condensate will begin to create a wave action. When the condensate fills up enough of the pipe cross section the wave action will eventually cause the condensate to block the entire cross section of pipe. When this happens the condensate then becomes a slug that us propelled by the force of the steam moving at 6000 ft/min. This slug will move down the pipeline until it hits an obstruction like an elbow or a tee creating a surge wave.

The same thing can occur in a steam condensate line if the system isn't sized properly or when upsets occur.

Question #5026: Can anyone tell me where to find weights for mortar lined pipework?
Please click here to offer your response. Reference Question #5026
Response 1: Try contacting the Ductile Iron Pipe Reasearch Association (DIPRA) at http://www.dipra.org

Question #5027: Does anyone know where I can find one of those steam slide calculators that help you size loops?
Please click here to offer your response. Reference Question #5027
Response 1: Calculator, yea, I know where you can get that calculator. Go to Wal-Mart and pick up a TI scientific, then open your B31.1 Code book to Paragraph 119.7.1 (A.3) and use that equation. B31.3 will have similar criteria but on a different paragraph.

Why are you in such a rush to make a mistake? Who are you going to trust your work to, a handy-dandy calculator who's origin is unknown, or the required code equations for design. Grinnell also has a fairly accurate method of analysis in their 'Piping Design and Engineering' book but that too is limited to specific general piping layouts. Fast is good for horses and plane rides, slow is better in design.

Question #5028: Where is a good place to look for piping design training?  I have been in the chemical field for 10 years but there aren't any training facilities near me.  I have been doing drafting (all disciplines) and mechanical design (Structural layouts, piping layouts, equipment layouts etc.) I am interested in becomming a full fledged piper.  Where should I look?
Please click here to offer your response. Reference Question #5028
Response 1: I don't know but when you find out let me know
Response 2: Ask your company to send you to the ASME B31.3 or B31.1 course. Buy  or go the a large University's library and get the standard bibles for piping analysis, Kellogg's book, 'Design of Piping Systems', Crockers 5th edition of 'Piping handbook', 'ITT Grinnell's Piping Design and Engineering Book', copy of ASME B31.3, 'Crane's Technical papers 410', 'Cameron's Hydraulic Data book',   Paul Smith's, 'Piping and Pipe Support Systems' to mention just a few. Be pro-active, start with the simple things, get to know your piping schedules, weights, and sizes, find out where and how B31.3 or B31.1 determines the minimum thickness of pipe. You say you already know how to draw isometrics, then learn the Code equation for determining flexibility in a piping system (determines whether you need a expansion loop or not). If you don't have anyone to mentor with dig up as much as you can on your own and submit questions on this web site. DON'T BE SHY! You can learn a lot just by digging up info but the best way to move forward is definitely the seminar route. Pay for it yourself if you have to, it's worth it.

Question #5029: Good morning fellow engineers,

I am looking for how is the ASME 31.3 Code applied for NON-METALLIC piping systems used for many chemicals in fluid and gas application.

The code does NOT list many plastic materials properties for PVDF, PFA, CPVC, PP etc.   The code only lists few thermoplastic material properties at ambient temperature and yet I do know that there are many types of NON-METALLIC piping systems used in food, pharmaceutical and the semiconductor/micro-electronics industries.  Doesn't the ASME 31.3 applied here for design, fabrication, inspection of NON-METALLIC piping systems and have the jurisdiction?

What can the design engineers use for pipe support design, fabrication, inspection, quality control and certification of many NON-METALLIC piping systems??

The fire code does NOT even refer to ASME 31.3 for the BASIC requirement of NON-METALLIC piping systems.  How can this be?

Also, what code is used for double contained NON-METALLIC chemical piping systems?

I will appreciate any help if you can shed some light on this subject.  

Thank you kindly.

Bart V. Makadia, P.E.

Please click here to offer your response. Reference Question #5029
Response 1: Depending on the scope of the project, either ASME B31.1, B31.3 or B31.9 would be the governing piping Code for utility piping systems and B31.3 would be the governing Code for process piping systems. This also includes the use of utility and process non-metallic piping.

What is referred to as the base Code, within B31.3, are Chapters I through VI. Subsequent Chapters VII, VIII and IX build from, and refer back to the base Code. In regard to non-metallic piping, covered in Chapter VII of B31.3, the same paragraph numbering system is used with the added prefix of 'A'. The corresponding number in the base Code and in Chapter VII will have the same subject matter. This allows for easy reference when the requirements are the same, and easy comparison when there are exceptions. This also applys to Chapter VIII, Category M piping with an 'M' prefix, and Chapter IX, High Pressure piping with a "K" prefix.

In regard to design requirements for non-metallic piping systems, you will find them, in varying degrees of thoroughness, in B31.1, B31.3 and B31.9. However, for composition and material testing requirements you will have to refer to ASTM standards. For pressure/temperature limits and mechanical properties refer to particular manufacturer.

Following are a few examples of ASTM standards that cover non-metallic material:

Specification D1784-99a Standard Specification for Rigid Poly(Vinyl Chloride) (PVC) Compounds and Chlorinated Poly(Vinyl Chloride) (CPVC) Compounds

1. Scope

1.1 This specification covers rigid PVC and CPVC compounds intended for general purpose use in extruded or molded form, including piping applications involving special chemical and acid resistance or heat resistance, composed of poly(vinyl chloride), chlorinated poly(vinyl chloride), or vinyl chloride copolymers containing at least 80% vinyl chloride, and the necessary compounding ingredients. The compounding ingredients may consist of lubricants, stabilizers, non-poly(vinyl chloride) resin modifiers, pigments and inorganic fillers.
Note 1-Selection of specific compounds for particular end uses or applications requires consideration of other characteristics such as thermal properties, optical properties, weather resistance, etc. Specific requirements and test methods for these properties shall be by mutual agreement between the purchaser and the seller.

1.2 Rigid PVC compounds intended for pipe, fittings and other piping appurtenances are covered in Specifications D3915 and D4396.

1.3 Rigid PVC compounds intended for building product applications are covered in Specification D4216.

1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.5 The following safety hazards caveat pertains only to the test methods portion, Section 11, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Specification D3915-99a Standard Specification for Rigid Poly(Vinyl Chloride) (PVC) and Chlorinated Poly(Vinyl Chloride) (CPVC) Compounds for Plastic Pipe and Fittings Used in Pressure Applications

1. Scope

1.1 This specification covers plastic compounds composed of poly(vinyl chloride), chlorinated poly(vinyl chloride), or vinyl chloride copolymers, and the necessary compounding ingredients intended for use in making pipe, fittings, and other piping appurtenances. The compounding ingredients may consist of lubricants, stabilizers, nonpoly(vinyl chloride) resin modifiers, pigments, and inorganic fillers.

1.2 This specification is designed to cover compounds for pressure piping applications. Refer to Specification D4396 for compounds designed for non-pressure applications.

1.3 Rigid PVC type compounds for building applications other than piping are covered in Specification D4216.

1.4 Rigid PVC type compounds for general purpose extrusion and molding use are covered in Specification D1784. Specification D1784 is applicable to piping applications involving special chemical and acid resistance.

1.5 The requirements in this specification are intended for the quality control of compounds used to manufacture pipe and fittings. They are not applicable to finished pipe and fittings. See the applicable ASTM standards for requirements for finished products.

1.6 It may be necessary in special cases to select specific compounds for unusual piping applications that require consideration of other properties not covered in this specification, such as service temperature, sag resistance, chemical resistance, weather resistance, bending forces, etc.

1.7 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

1.8 The following safety hazards caveat pertains only to the test methods section, Section 11, of this specification: This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Specification D4101-00 Standard Specification for Propylene Plastic Injection and Extrusion Materials

1. Scope

1.1 This specification covers propylene plastic materials suitable for injection molding and extrusion. Polymers consist of propylene homopolymer, propylene copolymers, and propylene-elastomer compounded with or without the addition of impact modifiers (ethylene-propylene rubber, polyisobutylene rubber, and butyl rubber), colorants, stabilizers, lubricants, or reinforcements.

1.2 This specification allows for the use of those propylene plastic materials that can be recycled, reconstituted, and reground, provided that: (1) the requirements as stated in this specification are met, and (2) the material has not been modified in any way to alter its conformance to food contact regulations or similar requirements. The proportions of recycled, reconstituted, and reground material used, as well as the nature and the amount of any contaminant, cannot be practically covered in this specification. It is the responsibility of the supplier and the buyer of recycled, reconstituted, and reground materials to ensure compliance. (See Guide D5033.)

1.3 The values stated in SI units are to be regarded as the standard.

Note 1--The properties included in this specification are those required to identify the compositions covered. There may be other requirements necessary to identify particular characteristics important to specific applications. These will be designated by using the suffixes given in Section 1.

1.4 The following safety hazards caveat pertains only to the test methods portion, Section 13, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Specification D3222-99 Standard Specification for Unmodified Poly(Vinylidene Fluoride) (PVDF) Molding Extrusion and Coating Materials

1. Scope

1.1 This specification covers melt processable molding and extrusion materials, as well as coating materials of poly(vinylidene fluoride) fluoroplastic, commonly abbreviated PVDF (or PVF2 in scientific literature). This specification covers thermoplastic resin materials supplied in pellet or powder form.

1.2 This specification applies only to the virgin homopolymer prepared from vinylidene fluoride, not copolymers, reinforced, filled grades or special grades with additives or treatments for modification of attributes.

1.3 The values stated in SI units and the practices of Practice E380 incorporated herein are to be regarded as standard except where common usage or test method specify common units acceptable within Practice E380.

1.4 The tests involved are intended to provide information for specification of unmodified PVDF homopolymer resins. It is not the purpose of this specification to provide engineering data for design purposes.

1.5 PVDF fluoroplastics melt between 156 and 180? (312 and 356?) and are thermally stable up to about 370? (698?).
Note 1-Evolution of corrosive and toxic hydrogen fluoride can occur under certain conditions.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Note 1 and Section 9.
Note 2-PVDF exhibits polymorphism. The type and extent of crystalline structure varies with the thermomechanical history of the sample. Specimens prepared by techniques different than prescribed in this specification could have properties that may vary from the values specified.

Good luck,

Bill


Question #5030: What does "spot faced" mean when referring to the facing of a flange?
Please click here to offer your response. Reference Question #5030
Response 1: Spot-facing, or back-facing, in regard to pipe flanges, is a machined area on a rough surface to provide a smooth contact area. Castings such as malleable iron and ductile iron, as well as FRP flanges, will usually be spot-faced on the back side (back-facing) of the flange to provide a smooth flush surface for a nut or, in the case of an FRP flange, a washer to be mounted on. 

Question #5031:   I have a situation where we are bolting new flow meters with a raised face flange to a flat face gate valve 125# class on existing cooling water and chill water service.  It would be very expensive and time consuming to have the raised faces turned down now if there is another way out. Is there any where I can look for answers to print out to back up a choice of leaving as is but maybe a different gasket arrangement or bolting material grade. The planned gasket use are Klinger C4401 and the operating pressures and temperatures are less than 100 deg F and 80 psig.
Please click here to offer your response. Reference Question #5031
Response 1: It basically depends on the governing Code for your project, or system. If B31.3 is the governing Code for the cooling/chilled water systems, then you cannot bolt the two flanges together. Assuming, that is, that the valve body is cast iron and the flow meter flanges are forged carbon steel. Refer to ASME B31.3, 309.2.3 - Bolting for Metallic Flange Combinations.  However, if the governing Code is ASME B31.9 then you are allowed to bolt the two dissimilar flanges together. Provided you use a low yield bolt such as A307 Gr B and, per ASME B31.9 para. 908.3, in part, "...When bolting raised-face steel flanges to flat-face cast iron flanges, bolt torque shall be limited to prevent cracking the cast iron; otherwise steel flanges should be furnished with a flat-face and full-face gaskets shall be used".

To limit cost, and prevent possible delays, I would suggest, if it hasn't already been done, you declare and document the governing code for those systems as ASME B31.9.
Response 2: How about using a Straub coupling to make your connection? Let me know if you require further info. cferguson001@aol.com

Question #5032: Where can I get design tables for pipe riser clamps? I am looking for some design data for pipe riser clamps for load rating and lateral movement. Would like to use riser clamps as lateral bracing.
Please click here to offer your response. Reference Question #5032
Response 1: Check out http://www.fastenersandtools.com/shop/hang5.html

Question #5033: We are looking for a Japanese suppliers for Carbon Steel pipes & Fittings for Sour Natural Gas services complying with NACE (HIC & SSC Testing)
Many thanks
.
Please click here to offer your response. Reference Question #5033
Response 1: I am in Japan.  If you can tell me a little more about what you need.  I can try to locate you a supplier.  Need to know what exactly you need and volume that you need as well as city of destination.

Regards,

Muna
BYJ Associates.

Question #5034:   I have to do an "assessment" of a 30+ year old steam and condensate distribution system for a large university.  To date, no one has defined how and what to check, or provided an industry standard, guideline or recommendation on how to test, where to test, and how many data points to look at.  If anyone has any practical experience in this, I'd appreciate the input.
Please click here to offer your response. Reference Question #5034
Response 1: There are actually three main components that should be checked when auditing a steam distribution, condensate collection system: The insulation,  pipe, and steam trap assemblies. Assuming the pipeline will remain online while the inspection is done, here is a basic breakdown of what needs to take place:

1. Insulation:
    A.  Walk the system down (if a system drawing, iso preferrably, is not available, create one) with drawing in-hand and make note of any sections where insulation has been damaged, removed, walked on, seams pulled apart, etc.
    B.  Indicate sections where insulation should be removed to inspect pipe for exterior corrosion.
    C.  For outside runs of pipe, indicate sections where water could have possibly gotten under the weather barrier and soaked the insulation. This can happen at
          damaged sections of insulation, or on horizontal runs where the overlap of the weather barrier is looking up allowing water to penetrate the seam.
    D.  Indicate removal of insulation at valves if the insulation covers the packing gland or if any sign of a packing leak is apparent.
    E.  Note: A cleaned up copy of this drawing can be used when assigning or bidding the work to an insulator. 

2. Pipe:
    A.  In advance, calculate the required wall thickness for each size of pipe in the system. Determine the minimum allowable thickness for each size.
    B.  Check wall thickness of pipe. There is a device out that will allow you to check wall thickness without removing the insulation. It is a gamma absobtion device with an advertised accracy of 2%. I have not used the device myself but it looks promising. There are other means of doing this that either require shutdown or insulation removal. If interested, you can check out the device at
http://www.ndt.net/article/wcndt00/papers/idn713/idn713.htm.
    C.  Points to check for wall thickness:
        1. Check the bottom of the pipe. This is where the majority of erosion, called grooving, will take place due to the formation of carbonic acid in the condensate.
        2. Check the outer bend of random elbows particularly those that are downstream from regulating valves. This is where superheating and high velocities occur. 
    D.  Record all data on a a copy of the same drawing as above. Assign numbers to each location where a thickness test is done for tracking.
    E.  Note: If the line is down (not likely) you could use a smart pig to check corrosion and wall thickness.

3. Steam trap assemblies:
    A.  Check each blowdown valve at every drip-leg, Y-strainer, and test valve. Determine and note (on a copy of the same drawing) which     valves are plugged closed with silt.
    B.  Perform an ultrasonic test on each trap to check performance. This is something that should be done on a regular basis by experienced personnel. Each trap should be tagged and numbered allowing a PM test history to be developed.

Depending on how well the boiler feed-water additives have been maintained, and how well the overall system was designed initially the system could still be in relatively good shape, or require a sizeable overhaul.

Generally, for a university job, you will find steam pressures in the range of 50, 30, 5 and 2 psig, or thereabout. Uses will range from space heaters to steam tables in kitchens. The main lines are usually fed from buidling to building via underground crawl spaces. The drawings I mentioned above will most certainly not exist. Your best bet is to acquire buidling layouts, walk the systems down and map out the piping systems on the building layouts. If you choose to do so, you can develop a system iso from those layouts. These older systems are generally over-designed with oversized steam traps and heavy wall pipe.  If you need added info contact Piping News.

Good luck
Response 2: I really get kick out of many junior engineers asking the important design type questions. You see nowadays, everyone wants to work on piping, vessel, heat exchangers etc.  But unfortunately no one seems to have any code experience or even wants to go through the proper training and experience. It is also unfortunate  to depend on this site to ask important design type question and hope for some one  would give an answer as long as the answer is not the case of "blind leading a blind".  I often wonder how well the clients are served and the public safety is achieved/maintained!!!

You need to read the ASME 31.1 code. 

All answers are in it.

Response 3: For the sender of response 2. The only thing worse than an arrogant engineer is an arrogant engineer that attempts to talk down to fellow engineers. Did it cross your mind that the guy or gal that asked the above question may have had this assignment dumped on their desk. The project they were assigned  may be out of his or her's expertise but at least they're making an effort to collect data from various resources to determine the best approach. If you have been around at all you have had projects handed to you in which you had to hit the books, and do a lot of research. This is how we grow and learn. A big component to that learning is gathering information from our fellow engineers. We help one another without looking down our nose from a self-perceived high perch. And while B31.1 will  answer many questions for the questioner, it will most certainly not answer them all. Codes set parameters, they're not a guide spec. 
Response 4: Be sure you take stoppered samples of the condensate with the view to testing for oxygen.  Space heating systems which condense the LP steam all the way to liquid HOH have had a past history of containing dissolved oxygen and is sometimes called "hungry" water since the oxygen will eat steel piping materials as well as valve internals, exfoliated the wall thickness... etc.  Good Luck!
Response 5: There is some Steam surveys that will help you get the ball rolling so you do not look like you are doing nothing. Bestobell makes an easy beginners steam survey that provides you step by step instructions on things to look for. I have to believe the university is implementing this due to high energy costs. Failed traps and poor insulation will be your biggest culprit. Invest in a sonic gun and a thermal gun. You need to use both in assessing the steam. If it has been 30+ years without a proper survey they better be ready for one hell of a bill. While your at it with the sonic gun go beyond the call of duty and provide them with a survey on there compressed air system as this is often an overlooked area which can cost many a wasted energy dollar. Also check out the United States Department of Energy web site they have done much research on this particular subject and should provide a lot of useful tools for you. There is a great deal more to this if you wish to do it correctly but Rome was not built in a day and you will have your hands full with just this. Be sure to label every trap and note it on a print of location so your work will not be wasted the next year and you do not have to start form scratch. I myself have done many surveys for many companies and it usually comes back to the almighty dollar and how much of it they are willing to part with so try to stick to the biggest waste culprits first then you may get into the redesign phase. Keep in mind on an old system nothing is perfect and you need to pick the worst and work from there. As for response 2 it is truly a sad day when we mock others but cannot share the knowledge we all have been blessed with. Somebody wrote the books you have learned from. Please keep that in mind.
Kevin Conklin

Question #5035: In the case of ESD in sour gas compressor Stations with inlet pressure more than 120 bar , should the flare gas supply be independent from the inlet gas for the station?
Should the pilot gas have continous flow apart from the gas of main station?

Please click here to offer your response. Reference Question #5035
Response 1:

Question #5036: I face a problem of removing  black HAZ after welding SS sheets. I have an equipment having 30 V AC out put. Please suggest me a most suitable chemical to clean the black/blue marks from the weld line.
Thanks.
Please click here to offer your response. Reference Question #5036
Response 1: If the discoloration you have is with austenitic stainless steel it can be removed by pickeling with a solution of 10 to 15% nitric acid plus 1 to 3% hydrofluoric acid. Spray or swab on to the discolored area at a temperature of 120 to 140 deg F. If it has to be done at room temperature use the higher levels of acid. You will have to experiment with the time period. Do one or more test samples to determine the most appropriate time the pickeling solution should remain on the discoloration before being rinsed. Rinse thoroughly with hot water. The cleaned steel will form a passive coat, in air, after the cleaning. For ferritic and matensitic stainless steels use an 8 to 12% sulfuric acid solution with 2% rock salt (NaCl) at 150 to 170 deg F. Spray or swab on the discoloration. Again, room temperature will take longer. Test for duration as before and rinse thoroughly with hot water.

Also check ASME A380 - Cleaning, Descaling and Passivation of Stainless Steel Parts, Equipment and Systems.

Good luck.

Question #5037: What makes the ASTM A105 as the universally adopted material for forgings?
Please click here to offer your response. Reference Question #5037
Response 1: Having been founded in 1898, ASTM currently has over 30,000 members in more than 100 countries. It has recently changed its name to ASTM International, implying its universal acceptance. ASTM A105 is only one of more than 10,000 standards published each year in the 73 volumes of their Annual Book of Standards. A105 and many other Standards are adopted and used universally.  ASTM may have originated in the US, but its current membership, adoption and input is universal. ASTM has signed a Memorandom of Understanding (MOU) with several countries.  Most recently with the national standards body of Colombia, Instituto Colombiano de Normas Tecnicas y Certificacion (ICONTEC) in Bogota, Columbia, and the Uruguayan national standards organization, the Instituto Uruguayo de Normas Tecnicas (UNIT).

Question #5038: Does ASTM A105 comes in two grades, Gr I and Gr II? If yes then does A105 implies A105Gr I?
Which metallurgical properties makes A105 a good forging material?

Please click here to offer your response. Reference Question #5038
Response 1: ASTM A105 does not come in various Grades or Classes. When specifying ASTM A105 forged components indicate ASTM A105 plus any special requirements such as heat treating for flanges ASME B16.5 Class 150 and 300 (Flanges Class 400 and above are automatically heat treated under A105).  If annealing, normalizing, tempering, or quenching is required  it needs to be specified. This also applies to fittings, valves and similar parts under A105 where heat treating may be required.

A material that can be shaped with low forces and without cracking is said to have a good forgeability. Usually forgeability competes with other desirable properties of the material and of the geometry of the workpiece, such as strength, corrosion resistance, toughness, fatigue resistance, heat resistance, size and section thickness. Therefore, the material is often selected on a compromise basis. The combined effects of temperature and deformation change the properties of the starting material. While it is often desirable to pick the starting properties based on compatibilities with the process, it is necessary to know or to be able to predict how the process will alter them.

So, to answer your second question, it is the balanced combination of metallurgical properties that make A105 a good carbon steel forging material.

Question #5039: Is there any thumb rule for guessing the Class rating(150lb, 300lb etc) of a piping component only by knowing the design pressure and design temperature and not refering ANSI B 16.5?
Please click here to offer your response. Reference Question #5039
Response 1: There is no rule of thumb for determining a flange Class under ASME B16.5. ASME B16.5 pertains only to flanges and flanged fittings. Pressure and temperature limits for other components  Classified as Class 150 and 300 are listed under separate Codes. The limits for malleable iron Class 150 and 300 threaded fittings are listed under ASME B16.3. The limits of cast copper flanges and flanged fittings are listed under ASME B16.24. The limits for gray cast iron Class 125 and 250 threaded fittings are listed under ASME B16.4. The limits for cast bronze Class 125 and 250 threaded fittings are listed under ASME B16.15.

With regard to B16.5 flanges, you need to know the material Class and design temperature in order to determine the pressure limits of a flange Class for the B16.6 Tables.

Question #5040: At what intervals shall we put steam trap assembly on the LP, MP or HP Steam lines? What are the engineering practices or guidelines that are followed for fixing the location or the requirement of the Steam trap assembly in a piping layout?
Please click here to offer your response. Reference Question #5040
Response 1: Intervals, no such thing as intervals in steam piping systems, (were not running water piping Buddy). You must trap steam systems at all low points in the system. You really need to get yourself some steam guidelines, Armstrong has some downloadable on the web (Steam Conservation Guidelines for Condensate Drainage, and Steam Traps, and Pressure Reducing Valves). Most states have guidelines on high pressure steam piping systems (over 15 psi). They are typically a bit more stringent that the ASME codes for construction of piping systems. Remember, this is power piping codes, boiler external, does any of this ring a bell? If not you need to talk to a Armstrong or Spence or TLV engineer to get yourself a bit more up to speed on the dangers of steam piping. Most pipefitters go through 5 years of training to attain the high pressure steam license to install steam systems. Many good books out on steam design but few on actual installation. Take the time to learn about steam before you design or install, it's a dangerous beast.
Response 2: I am Union Pipfitter with a great deal of experience in steam. As I think knowledge is key and everyone should share if you email me I will give you some general guidelines and some good points of reference. Please do not hesitate to ask me anything because I am a tradesman as with anything you should never judge a book bye its cover.
Kevin Conklin
Conch10@aol.com

Question #5041: Does anyone know of any technical papers or magazine articles written about the problem of attachments  to piping that crack at the weld?  In particular, pipe shoes or plates that have a continuous fillet weld to the pipe wall and that extend out past the insulation setting up the condition for thermal stresses due to the weld being at pipe temperature and the exposed end of the shoe or plate being at or near ambient.
Please click here to offer your response. Reference Question #5041
Response 1: See if you can find an “OLD” ITT Grinnell hard cover book. If I remember right there is “NO” continuous fillet weld!  About in the center there is a brake in the shoes back cut out of the I beam, the reason is to stop the cracking of the weld. Thermal stresses. I hope this is some help.

Thomas Kehl
 

Question #5042: I am hoping someone out there can help me. I would like info, literature on API 1104 Overland Piping. Any HELP would be gratefully appreciated.
Kind regards,

Steve Fawcett
Please click here to offer your response. Reference Question #5042
Response 1: API Standard 1104 - Welding of Pipelines and Related Facilities covers gas and arc welding for the production of high-quality welds in carbon and low-alloy steel piping used in the compression, pumping, and transmission of crude petroleum, petroleum products, and fuel gases, and where applicable, to distribution systems. It covers many different types of welding processes for the categories mentioned. It would help if you had a specific question.
Response 2: Thank you for your response. Having studied API 1104 8th Ed 1994, I would like to be able to go several more steps"e.g." instillation procedures, equipment used, requirements asked of works foreman, etc.
Thank you for your time.
Kind regards,
Steve Fawcett
Response 3: I guess the way forward is to look at he specific Design Code that your Overland Pipeline is designed to and from that get the information that you want. Most Pipeline Code like ASME B 31.11, PD 8010, AS 2566 etc have specific Chapter on Fabrication and Installation. These Vary from Code to Code and so I think the important thing is to start from the Basic Code that your Pipeline is designed to.

Naresh Balakrishnan
Materials and Technology  Engineer
Goro Construction Team

Question #5043: What design criteria should be used in sizing a knockout drum for prevention of liquid carryover to a process flare?  What are the advantages of vertical versus horizontal?

Ryan Powell
Schenectady International, Inc.
Please click here to offer your response. Reference Question #5043
Response 1:

Question #5044: Is there anybody out there that can help me?? I am british and living in the Netherlands, in the Rotterdam area, and have a desire to become a piping designer but I have no idea what courses are the best to take and if they are in English. Would I have to take a piping course separate from a computer course or is it possible to study them together in one course? I am concerned that the wrong training will limit my job prospects. Are there any companies that offer apprenticeships? Any help would be gratefully received.
Thanks,

C. Jago
Please click here to offer your response. Reference Question #5044
Response 1: All of us "oldtimers" learned from Process Piping Design by Rip Weaver. You can find this book on Amazon.com. Idon't believe any really usable couirse on Piping Design is taught anymore. Your best bet is to try and get an AutoCAD job revising P&ID's etc. Starting off as a junior drafter and work your way up. Piping Design is something that is not easily taught in a school course environment. My personal opinion is that if you want job security pursue becoming an electrical designer. Take it from me, I have been a senior Piping Designer for over 30 years and it has been a roller coaster ride. Rod
P.S. I lived in the Hague as a small boy. I would love to live there again. Any suggestions on how to get work there. It is my ardent desire to become an expatriot. Rod

Question #5045: What is the best way to make a super-heated steam chamber in a lab to be used by a college student?
Please click here to offer your response. Reference Question #5045
Response 1: The best resource for the information you need is the companies that actually utilize these lab systems on a routine basis. That would be the manufacturers of steam traps and other miscellaneous steam related equipment such as Armstrong, Spirax/Sarco, Yarway, Nicholson, etc.

Of those companies, the best place to start would be with two of the manufacturers: 1.   Armstrong International. You can reach them through their web site at http://www.armintl.com/products/traps/st.php3 . Click on the "Talk to Us" link and ask them if they can provide you with diagrams, equipment and other essential information for building a laboratory sized superheated steam manufacturing system. They have lab systems they use for their own testing and demonstrations of steam related equipment.

You can also check with Spirax/Sarco through their representative in Indianapolis, IN. The rep. is Fink & Company, P. O. Box 114, 222 E. St. Joseph St., Indianapolis, IN 46206, Phone: (317) 639-1551, Fax: (317) 684-4284. Explain to them what your needs are and they will most likely provide you with the necessary information. You can also check out their web site at http://www.spiraxsarco-usa.com/.

Good luck

Question #5046: Hello:
Can anyone tell me if the pipe from a once through boiler to a steam driven turbine with a temp of approx 1000 degrees F and a pressure of approx 900 PSI needs to be graded or trapped. There are provisions for draining the pipe at startup. (eg) three valve stations. We had what would seem to be water hammer which moved the pipe a considerable amount when running. So much so, that it distorted the pipe.
Thank you

Please click here to offer your response. Reference Question #5046
Response 1: You need to both slope the line in the direction of flow and install the proper steam traps in strategic locations. If you have water hammer you will definitely know it. The force in water hammer, particularly in steam lines, could have enough force to distort pipe, rip out or shear off supports, and lift equipment off their foundation pad. If you don't hear the water hammer (you did not mention the hammering or banging noise associated with water hammer) then the pipe distortion could be the result of poor expansion calculations. If the configuration of the piping does not allow for sufficient flexibility for the expanding pipe it will distort between anchors. Additionally, if you are accumulating enough condensate in your superheated steam line to create the slug flow causing the water hammer you may have other problems.


Question #5047: I need to determine the minimum input track dimensions (up to the point of the surge protection) for a board layout that needs to be able to handle a very high input surge current (5kA 8/20us current pulse). Can anyone help?

Thanks,
Brett

Please click here to offer your response. Reference Question #5047
Response 1:

Question #5048: Dear Sirs,

I am a student and am currently doing two different projects for university and need some information regarding these problems:

1. I am looking for some general information on bringing a water borehole on stream. The water is to be used in a brewery.

2. I am also looking for information on how to build a pipeline to pump water from a reservoir to a brewery 3.5 miles away (the height difference is about 300 yards). Any information on pipe sizes, construction materials, surface finishes, cost per meter, pressure ratings, pumps, valves and fittings... would be very helpful.

If you could help me in any way I would be very thankful.

Best regards,

Florian Kuplent

Please click here to offer your response. Reference Question #5048
Response 1: I can send you information on specifications, materials, piping design, and brewery process. I am not that good with fluids and pumps but it sounds like you need the Crane 410 book and a little guidance. What is your timeline?

Question #5049: Plant design Software : I would like to know the feedback on the Bentleys "PLANT SPACE" & CEA technologies "PLANT 4D" software. If any one has used it. Kindly give us your practical advice, As we are in process of evaluation of the software for our company.

Best Regards

Shekhar Sali

Please click here to offer your response. Reference Question #5049
Response 1: The "Bentley system" Intergraph MicroStation®, Power Draft Bentley, ®  are known for being a open system. I have not been told of any thing bad about system. But what you should look at is the training cost after words and the time it takes.
Thomas Kehl

Question #5050: Could I know the cost for PWHT work of plant piping in US ?
Please click here to offer your response. Reference Question #5050
Response 1: Contact you local Heat Treating Vendor near you for estimates. They will probably be happy to give you rough estimating tables for specific time/temperature jobs, given your material or pipe size.


Question 5051: How do you calculate the quantity of steam flow through a slot in the steam pipe?
Please click here to offer your response. Reference Question #5051
Response 1: You will have to estimate the size of the opening,  transpose that estimate into a diameter,  then calculate it as steam flowing through a square edged orifice the size of which you have estimated.

Question 5052: I am an Engineering graduate from Nigeria. I want to know if there is any software I can acquire that put me through 3-d piping designs and how can I get it?
Please click here to offer your response. Reference Question #5052
Response 1: There are various Piping 3D softwares available like ..
PDS, PDMS, Plant 4D, AutoPlant, Cadison, Plant Space, Propipe, Etc..

You need to get training of the softwares before use/ Job.
Best Regards
Shekhar Sali

Response 2:


Question 5053: Does anyone know where I can get a copy of "Design of Piping Systems" by
M.W.Kellogg?  I would take a "real" copy or scanned pages of the manual.  I
can be contacted at steve.butler@shell.com.

Steve Butler, P.E.

Please click here to offer your response. Reference Question #5053
Response 1: Most of your larger University Libraries have the 1956 edition which is still as good as the 1965 edition. The book is out of print and I have had a request into at least six different books searches for it for the last year. The only way you are going to get a copy is to check it out of the library. What you do with it after that is your business.
Response 2: I have seen several copies on the internet, at used book sites such as Alibis or Addall. If you keep looking you'll eventually land a good one.
 


Question 5054: I am trying to design a section of pipe which will be used instead of a restriction orifice. I would like to know weather there are any documents which contain information of the calculation of pipe erosion caused by flowing water (50 m/s)

Please click here to offer your response. Reference Question #5054
Response 1:

Question 5055: Dear friends: I have a water transfer pump with 7 liter/sec @ 4 bar head. According to site condition where this pump will be installed:

1.       The water tank is under ground and there is a differential static head 2.1meter between the pump and the lowest point in the tank.

2.       The total length of the pipe run is 20 meter.

3.       There are 5 no. bends 90 deg. Each.

4.       There is 1 no. foot valve.

5.       The pipe is HP PVC and the size can be 2", 21/2" or 3" or any.

 My worry is: Does the pump will function properly? Without any problem with the suction line [such as; cavitations, air sucking or any other problem]. What is the self primer pump means? And will this pump be better according to these conditions?

Thanks.

Please click here to offer your response. Reference Question #5055
Response 1:

Question 5056: I need to calculate the anode wt for 8" piles supporting two platforms and a walkway connecting them. Total no of 8", 12m long pile used are 4 each under each of the 2 platforms and 6 nos under the walkway. How to calculate the anode wt? Or advise for any help /or sample calculation available on the internet.
thanks
JS

Please click here to offer your response. Reference Question #5056
Response 1:

Question 5057: I am trying to source the steam piping for the installation of 9 turbine generators in Asia.  Could anyone provide me with the source for this chrome-molly pipe up to just over a meter in diameter?

Contact me via email at shawnw@turbinegenerator.com

Please click here to offer your response. Reference Question #5057
Response 1: I would suggest Benteller in Germany for Chrome Moly Tubing and Piping. Naturally you will have to check if they can do the sizes that you want.

Naresh Balakrishnan
Materials and Technology  Engineer
Goro Construction Team

Question 5058:  I want to take up PDMS Course. Can anyone provide me, the contacts, for doing this course, possibly in India.....

Plz. guide ,
Kiran

Please click here to offer your response. Reference Question #5058
Response 1: PDMS Course is available at MIT, Pune, India  of Approx 2 Months...You may visit the MIT Pune web site & get more details.
Best Regards
Shekhar Sali

Response 2:
 

Question 5059: Here is my question:

 

I have pressure / flow taps in a pipe line 20” P22 [Approx. 4.5” wall, with Design Pressure = 3860, design Temperature = 1006 Deg. F. Line bore of ½”.

Here is the problem; we are going to remove the taps. Use a 2” Dia. Plug drill/bore into the pipe about 2” Long. This will leave a 2 -1/2’ X ½” Dia hole that has to be filled.

So if we cut the line bore hole at a 45Deg. Cut, and weld closed this opening to slow down or stop erosion in the area, keeping in mind that there will be some protrusion of weld into the flow.

What Welding Rod i.e. root pass, filler. act?

At what level should the x-Rays be taken? i.e. every inch?

What preheat should be used for how long or temp should we have?

What post heat and for how long?

 

T. Kehl

Please click here to offer your response. Reference Question #5059
Response 1:

Question 5060: how to calculate the piping load in the rack?

Please click here to offer your response. Reference Question #5060
Response 1:

Question 5061: My fiance has recently accepted a PDS job here in SC. He has been to 2 short training courses, but I would like to supply him with more information on PDS 3d and P&ID. Is there another way, besides training out of state by Intergraph(or so I think it was them), for him to learn this system? Are there books to teach him how to draft/draw?

Please click here to offer your response. Reference Question #5061
Response 1:

Question 5062: What is flare knock out drum?

Please click here to offer your response. Reference Question #5062
Response 1
: The knock out drum is the final step before the gas reaches the flare stack in which any particulates that may be entrained in the flowing gas stream will be removed. This is usually done by directing the flow of gas into the knock out drum through a tangential entry nozzle. This utilizes centrifugal force to separate out the heavier than gas particles, allowing the gas to continue on to the flare stack and the heavier particulates to drop out. There are other methods, but that is essentially the idea.

Question 5063: Which valve is better for on/off operation in process lines, whether gate valve or butterfly valve or triple eccentric butterfly valve, with respect to cost, leakage and life. What is triple eccentric butterfly valve how it is different from ordinary valve?

Please click here to offer your response. Reference Question #5063
Response 1: Specifying the correct on/off valve is dependent upon the fluid service and the design conditions of the system. The valves you listed, including also the ball valve and plug valve, are acceptable valves and should be specified based on multiple criteria.

With regard to butterfly valves, there is the standard, or non-offset valve, the double eccentric (or double offset) valve, and the triple eccentric (or triple offset valve). The standard (non-offset) butterfly valve has a resilient rubber type seat, which limits its operating temperature. Its pressure is limited to somewhere around 150 psig, depending on its design and seat material. The shaft of this type valve is on the centerline of the pipeline and the valve. Whenever the stem is rotated to open or close the valve there is friction between the disc and the seat, which creates a wear point.

The offset valves are what are referred to as high performance butterfly valves. The centerline of the shaft on these valves is offset from the centerline of the valve and the pipeline. As the disc is rotated to open or close the valve’s camming action rotates the disc to line it up with the seating surface and then moves the disc into the valve seat in a motion that is along the centerline axis of the valve opening.

The seating action of this type valve allows the use of other types of seating material such as PTFE, RPTFE, etc., raising the allowable operating pressure and temperature of the butterfly valve. The triple-eccentric valve design accommodates metal to metal seating allowing for even higher pressures and temperatures.

Question 5064: Is the diameter of butterfly valves governed by pipe schedule?

Please click here to offer your response. Reference Question #5064
Response 1: No.

Question 5064a: I heard that 3D distance should be maintained in upstream and downstream of swing check valve to avoid chattering of disc, is this correct?

Please click here to offer your response. Reference Question #5065
Response 1: Valve chatter is not due to turbulent flow. It is indicative of an oversized valve, which is the repeated opening and closing of the valve, which occurs when the valve is only partially open. When the valve opens, there is a drop in the upstream pressure. In an oversized valve this differential pressure across the valve may fall below the required opening pressure. The valve will then slam shut. As soon as the valve closes, the pressure begins to build up again, and so the valve opens and the cycle is repeated. This occurs in rapid succession causing a chattering noise.

Question 5065: When a check valve is installed fitting to fitting down stream of gate valve will pressure drop in gate valve cause chattering in check valve.

Response 1: Valve chatter is not due to turbulent flow. It is indicative of an oversized valve, which is the repeated opening and closing of the valve, which occurs when the valve is only partially open. When the valve opens, there is a drop in the upstream pressure. In an oversized valve this differential pressure across the valve may fall below the required opening pressure. The valve will then slam shut. As soon as the valve closes, the pressure begins to build up again, and so the valve opens and the cycle is repeated. This occurs in rapid succession causing a chattering noise.

Question 5066: What’s the difference between variable spring support and constant spring support?

Please click here to offer your response. Reference Question #5066
Response 1:  A variable spring support is simply a pipe support that utilizes a spring to absorb movement in a pipeline. However, as the coil of the spring compresses from the load the point load on the pipeline will vary. Because of this variable load at any given point in the pipeline the piping system can experience an unequal distribution of stress to the piping system.

The design of a constant load support compensates for this by maintaining a constant load on the pipe as the pipe moves during expansion and contraction. By maintaining a constant load at these various load points in the piping system it prevents an uncontrolled transfer of loads to other parts of the piping system preventing over stress of the system.

Question 5067: As per OISD118, aggregate capacity of tanks located in a dike wall enclosure shall not exceed the following values:

60,000 cum. for a group of fixed roof tanks.

120,000 cum. for a group of floating roof tanks

Why is this?

Please click here to offer your response. Reference Question #5067
Response 1:  Not aware of OISD118. For calculating the volume a secondary containment (dike) area is to be sized for the most widely accepted practice comes from 40CFR112.7(e). It states that secondary containment should be sized to accommodate the volume of the largest single tank in the drainage area plus sufficient freeboard for precipitation. Accepted practice allows this to be calculated by using a multiplier of 1.1 times the capacity of the single largest tank within the dike area. Another practice is to use 100% of the capacity of the largest single tank plus a volume of rain over a 24 hour period based on a 10 year or 25 year storm.

There is no differentiation made between fixed roof and floating roof tanks. It is all based on capacity.

Question 5068: What is the difference between a drip leg and a steam trap?

Please click here to offer your response. Reference Question #5068
Response 1: A drip leg is a vertical section of pipe that provides a place for condensate to collect outside the main flow of steam. The condensate will run down into the drip leg as the steam continues to its user (equipment). Near the bottom of the drip leg is a take off for the steam trap. As the condensate accumulates in the drip leg it will flow to the trap and be carried off in a condensate return line.

The steam trap acts as a barrier that prevents steam from escaping, while allowing condensate to be removed.

Question 5069: What is the difference between 2d and 3d expansion loops in piping? How do 3d loop works?

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Response 1:  We have never heard expansion loops referred to as 2d and 3d before, but what it most likely refers to are single and multi-plane expansion loop configurations. It sounds like terminology that may have come from CAD design. If that is the case, then 2d would refer to a single plane configuration in which a 'U' bend expansion loop would be in the same plane as the pipe run. 3d would refer to a multi-plane configuration in which the piping would rise up and (using the 'U' shape again) form a 'U' configuration in a plane other than that of the pipe run. The multi-plane configuration can absorb more expansion than the single plane. 
Response 1: What would be the estimated Ratio difference between the 2d and 3d loop ?

Question 5070: What are the limitations of a fillet weld with respect to weld size. Can a 6mm fillet weld be done on both of plate of 6mm thick? Will plate thickness affect weld size?

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Response 1: For static loads the calculation for determining fillet weld size is .707 x minimum metal thickness. Or, you can say the leg of the fillet weld is equal to the thickness of the thinner material. For dynamic loads you need to have an engineer, experienced in welding, make the calculation and determination.

Question 5071: Is it allowed to make fitting to fitting connection in process pipe line?

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Response 1: Yes.

Question 5072: Can a gate valve be mounted with hand wheel vertically facing down or horizontal in process lines?

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Response 1: It is recommended that a valve not be installed in an orientation that would place the handwheel in a position below horizontal. About the horizontal axis of a pipeline, the handwheel should not lie lower than a few degrees above horizontal, but certainly no lower than horizontal.

If a valve handwheel is inverted in a steam system it would allow condensate to collect and corrode the valve bonnet and internals. In a process fluid line, as you mentioned, a dead leg is created when the valve handwheel stem is inverted, or below horizontal. This pocket, or dead leg, in the valve bonnet allows particulate to accumulate, possibly to the point of interfering with valve operation or the process fluid itself. It also presents a problem if the valve has to be repaired. If the liquid is caustic or acidic it would be difficult to pull from or repair in the line. Orienting a valve stem in a position below horizontal is not a good practice.

Question 5073: What is hammer blind valve? As far as my knowledge is concerned it is used in ATF service, why is this?

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Response 1: The name "hammer" blind valve actually comes from the Hamer Line blind series of blinds. The Hamer line blind valve is simply a mechanized version of a line blind. It allows for a single person to insert a blind into a pipeline where one is frequently used. There are other manufactures that now make these types of blinds besides Hamer. These are not actually a valve in which you can shut off flow in the pipeline by turning a handle. The fluid service has to be shutdown, the blind put in place, and the fluid service restarted. Some of the designs may look like a valve, but they are not actually a valve.

Question 5074: What is IBR? When we will go for IBR approval for pipes and at what temperature and pressure.

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Response 1: If you are in India IBR stands for Indian Boiler Regulations. They regulate and certify boiler equipment and steam piping within India.

With regard to boilers, they cover any closed vessel exceeding 22.75 liters in capacity that is used expressively for generating steam under pressure. This includes any mounting or other fitting attached to such vessel which is wholly or partly under pressure when the steam is shut off.

From a piping standpoint they cover any pipe through which steam passes from a boiler to a prime mover or other user or both if the steam pressure passing through such pipes exceeds 3.5 kg/cm2 above atmospheric pressure, or such pipe exceeds 254 mm in internal diameter. 

Question 5075: What is the difference between jacketed piping and steam or electrical traced piping? And when they are used.

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Response 1: Jacketed piping is where you fabricate a pipe inside a larger pipe. Spacers are mounted (welded) on to the OD of the smaller pipe so that when the larger pipe is installed over the smaller pipe the spacers maintain an annular space equa-distant around the smaller pipe. The larger pipe is necked down (reduced) to the OD of the smaller pipe on the backside of each flange joint. Jumpers, about 3/4" NPS, connect the larger pipe jackets on both sides of the flange joint.

Jacketed piping is used when heat transfer is necessary to keep the fluid in the smaller pipe above or below a certain temperature. Steam or electrical heat tracing provides enough heat to only keep a pipeline from freezing when outside temperatures get below freezing.

Usually jacketed piping will carry Dowtherm, Thermenol, or some other heat transfer fluid to either maintain the fluid at a hot temperature or cold temperature along the length of the pipe run rather than rely on one localized heat transfer point such as a heat exchanger. Heat exchangers are still used, but the temperature has to be continually maintained along the entire length of the pipe. As an example, when liquefying a polymer from polymer granules or pellets it will have a tendency to re-solidify. In order to maintain its liquid state in the pipeline for transport heat has to continually be applied to the pipeline. This is done with jacketed piping.

Question 5076: What is the difference between metallic and non metallic gaskets? And where are they used.

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Response 1: ASME B-16.5 - Pipe Flanges and Flanged Fittings, lists 16 different types of gaskets. In this listing are various forms of metallic gaskets. The metallic types of gaskets listed are:

1. spiral-wound metallic with nonmetallic filler;
2. corrugated aluminum, copper, copper alloy, or corrugated aluminum, copper, copper alloy double jacket with nonmetallic filler;
3. Corrugated metal, or corrugated metal double jacket with nonmetallic filler;
4. Flat metal jacket with nonmetallic filler;
5. Grooved metal
6. Solid flat soft aluminum;
7. Solid flat metal; and
8. Metal ring joint

As you can see there are several different variations of metallic gaskets. Without taking you through the entire thought process of determining when and where to use a specific type and material of metallic gasketing we will simply say that the decision is driven by the contact fluid, design pressure and design temperature. Metallic gaskets are usually selected for high pressure and/or high temperature service conditions. The selection of the type and material of gasketing should be done by an engineer with the experience to do so.

Question 5077: How much should be the free run distance in upstream and down stream distance in orifice meter in case of process pipeline? Why it is required?

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Response 1: A high degree of turbulence, such as what would be detected immediately downstream of an elbow, will have an adverse effect on the meter's detection of the flow. To allow the meter to detect flow in an accurate manner it requires a more streamline flow characteristic. The straight run of piping upstream allows turbulence to dissipate. The downstream straight run prevents back pressure or back surges from having an effect on the meter. 

Question 5078: What is NPSH in pumps?

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Response 1:NPSH is an acronym for Net Positive Suction Head. The Hydraulic Institute defines NPSH as the total suction head in feet absolute, determined at the suction nozzle and corrected at datum, less the vapor pressure of the liquid in feet absolute. In other words, it is an analysis of energy conditions on the suction side of a pump to determine if the liquid will vaporize at the lowest pressure point in the pump.

If the liquid level on the suction side of a pump falls below the NPSH value the pump will cavitate. When this occurs it sounds like gravel moving through the pump. This is a loss in efficiency and detrimental to the pump. 

Question 5079: Why pipes are standardized based on outside dia instead of inside dia? For example if I say 36" pipe it should represent inside dia but it is not, it is referring to outside dia and inside dia depends on the thickness we specify.

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Response 1: Nominal Pipe Size (NPS) does not match the pipe OD until you get into sizes in excess of 12" NPS. Pipe 14" NPS and larger will have the same OD as the size specified. If you specify a 20" NPS pipe the O.D. will be 20". Pipe sizes 12" NPS and below will have varying O.D.'s that are nominal to the size specified. If you order a 12" NPS pipe it will have an O.D. of 12 3/4", a 3" NPS pipe will have an O.D. of 3 1/2".

There are a couple of reasons for this strange aspect of pipe manufacture, as well as the fact that any increase in wall thickness reduces the internal pipe area rather than being added to the O.D. of the pipe.

Pipe was initially sized (prior to the late 1800's and early 1900's) based on internal diameters. When industry began standardizing on both pipe and fittings at the turn of the 20th century it became obvious that the O.D. of the pipe and fittings would have to be fixed, while any change in the pipe wall thickness would have to be accommodated on the inside of the pipe.

This allowed everything from pipe threading machines, to the I.D. of threaded flanges, slip-on flanges, socketwelded fittings, threaded fittings, etc., to be standardized based on a fixed pipe O.D.

The reason that the 14" NPS and larger pipe has an O.D. respective of its specified size is due to flow value. Pipe sizes 12" NPS and smaller are nominal to the inside diameter of the pipe. Nominal meaning that a 12" NPS with a Std WT pipe will have an internal diameter (11.938") close to that specified. Specifying a wall thickness other than Std WT will make the I.D. more than, or less than the NPS specified. Based on the cross-sectional values of the pipe I.D.,  when calculating flows in the smaller pipe sizes those internal size increments, from one wall thickness to another, can have more of an impact on the flow to size ratio than they would have in the larger pipe sizes. Meaning that by establishing the pipe O.D. on the larger pipe sizes, 14" NPS and above, to equal the value specified (14" NPS = 14" O.D.) and allowing the thickness to encroach into the pipe I.D. value, has no significant impact on the flow to size ratio.

The bottom line is, these sizes are fixed in the engineering, manufacture, fabrication and installation of pipe and all of its ancillary equipment and components. As long as you use the standard I.D. values in your flow calculations, and listed thickness values in your stress calculations it should all work together.

Question 5080: Where I can get details of pump piping? Any websites plz.

Please click here to offer your response. Reference Question #5080
Response 1: One of the best sites for pump design info is http://www.gouldspumps.com/cat_pf_0001.html.

Goulds, now owned by ITT, started publishing fundamental pump design information in book form close to 40 years ago. They have taken that information and now publish it on their web site. This is an excellent source of pump data. You can link on the subject matter in the middle of the linked page and also under the Navigation links on the right side of the page.

Question 5081: In pump suction pipe t-type strainer is provided, can it be kept in horizontal plane? If not, which position is correct and what is the reason?

Please click here to offer your response. Reference Question #5081
Response 1: What you are most likely referring to is a suction diffuser. This isa device that acts to distribute and streamline flow into the suction of the pump to help provide optimum flow conditions to improve pump efficiency. There are various designs, but typically it will have an internal plate with a series of holes throughout the cross-section of the flow stream. Flow is forced through these openings, which removes much of the turbulence and provides an evenly distributed cross-section of flow. They are also provided with a startup strainer, which is accessed via the branch part of the 'Tee'. The Suction Diffuser should be located close to the pump in the horizontal with the branch, or startup strainer access in the vertical. 

Question 5082: In pump discharge why check valve is kept in upstream of any valve?

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Response 1: In situations in which the pump might experience repeated back surges, a check valve is installed in the pump discharge in close proximity to the pump, and upstream of a block valve. An example would be a tandem pump installation with one pump acting as an installed spare, or as an automated method to increase flow rate. The check valve would prevent a surge impact from one pump effecting the performance, or even damage from the other pump. This type installation would normally require a swing check installed in the vertical with a 1/4" hole drilled into the disc to allow the piping upstream of the block valve to be drained.

Question 5083: Can a gate valve & butterfly valve be used for flow regulation purpose? If not why?. Which valve serves this purpose?

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Response 1: While the globe valve and needle valve (for small tubing lines) are typically selected for flow control, the butterfly and ball valve can also be used for flow control. There are various trim designs available (which we will not elaborate on) in the globe and ball valve designs depending on the regulating requirements of the valve. The globe and needle valve designs can provide a more finite control than the others.

Question 5084: What is the reason for using rods on sleepers? I heard that it is to reduce friction, but friction does not depend on area of contact.

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Response 1: This comes from designers or engineers theorizing about friction load and/or corrosion issues and arriving at an impractical solution to a non-issue. If friction load is a real concern then use Teflon slide plates. If corrosion is a concern then add a wear plate or select a more appropriate material of construction. Using 3mm rod, or some other diameter rod, is not a practical solution to such a theoretical problem.

Question 5085: Then what is the use of rod on sleeper?

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Response 1: You do not need rods on sleeper supports. As stated above, if the determination is made that there is a possible unwanted friction load from pipe movement on the sleeper then specify slide plates. If the possibility of corrosion exists, then ensure that a proper material of construction is specified that will stand up to the corrosion. 

Question 5086: Can stainless steel flange be mated with carbon steel flange? If not, why? And how it can be mated is there any possibility.

Please click here to offer your response. Reference Question #5086
Response 1: Bolting or threading dissimilar metals together can create galvanic corrosion of the lesser metal. The lesser metal will act as a sacrificial anode to the more noble metal. If you need to bolt two dissimilar metallic flanges together it is best to use what is called an isolator kit. The only thing that connects the flanges is the bolting. The bolts act as a conduit for the electro-chemical activity between two sets of flanges. Using an isolator kit breaks that bond and prevents the electro-chemical activity that causes the galvanic corrosion.

Question 5087: What is static electricity in pipes? How to avoid it?

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Response 1: Static electricity, or charge accumulation, is the result of charge generation not able to dissipate to ground readily. If a charge generated in a pipeline from a flowing fluid is allowed to dissipate to ground, as it does in grounded metallic pipe, then there is no problem. However, if a charge cannot dissipate, as experienced with thermoplastic pipe, and thermoplastic lined pipe, and is allowed to accumulate, it now becomes a problem by potentially becoming strong enough to create an Electrostatic Discharge (ESD).

For more information on this topic we will refer you to the William Huitt article in the July 2007 issue of Chemical Engineering magazine.

Question 5088: How static electricity is formed in process pipe lines?

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Response 1: As a fluid moves through a pipeline it creates friction against the pipe wall. This friction creates an electrical charge, referred to as charge generation. The amount of charge created by this friction is dictated by the chemistry of the flowing fluid and its velocity through the pipeline, or the higher the velocity, the higher the electrical charge.

In metallic piping systems the electrical charge is dissipated through the pipe wall and runs along the pipe until it reaches ground, either through grounded equipment or through grounding straps connected to the pipeline.

However, when fluid is flowing through thermoplastic lined pipe, or solid thermoplastic pipe it cannot dissipate because this material is generally nonconductive. Because the electrical charge cannot dissipate it accumulates and you now have Internal Charge Accumulation (ICA). This is unique to thermoplastic lined pipe and solid thermoplastic pipe.

Without being impregnated with a conductive material, thermoplastics are not good conductors of electricity. PTFE (Polytetrafluoroethylene), as an example, used as a pipe liner, has a high (>1016 Ohms/Square), resistively factor. This is a relatively high resistance to conductivity. This means that any charge created internally to the pipe cannot readily be conducted away to ground by way of the PTFE liner.

Instead the charge will be allowed to build until it exceeds its total dielectric strength and burns a pinhole in the liner to the internal metal wall of the casement pipe. It isn't charge generation itself that is the problem, it's the charge accumulation. When the rate of charge generation is greater than the rate of charge relaxation (the ability of material to conduct away the generated charge), charge accumulation occurs.

The dielectric strength of PTFE is 450 to 500 volts/mil. This indicates that for every 0.001" of PTFE liner 450 volts of triboelectric charge will be required to penetrate the liner. For a 2" pipeline with a 0.130" thick liner this translates into 58500 volts of triboelectric charge to burn through the liner thickness.

The charge generation can be retarded by reducing fluid velocity. The following table is from BS 5958 and suggests fluid velocity maximums based on the fluids conductivity.

For more information on this topic we will refer you to the William Huitt article in the July 2007 issue of Chemical Engineering magazine.

Question 5089: what are the basic types of steam traps and were they are used?

Please click here to offer your response. Reference Question #5089
Response 1: Please read the article, by William (Bill) M. Huitt, on steam that we have posted at http://www.pipingnews.com/steam1.htm. This article will explain the different types of steam traps and much more.

Question 5090: What is stub in and stub on connection in process pipeline? What is the difference and in which situation they are used? Where it should no be used?

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Response 1: There is no such thing in piping as a "stub-on." You can sometimes make a stub-in connection when you need to make a branch off of a pipeline. The reason I say sometimes is because the design pressure/temperature may be above the allowable limit of the stub-in connection. This type fabricated connection takes the place of a manufactured tee. It can be an unreinforced connection or it can be a reinforced connection. There are three types of stub-ins shown in ASME B31.3: Types a & b are unreinforced. Type c is reinforced. There are also manufactured reinforcement fittings called olets (weldolet, threadolet, etc.).

Question 5091: Will turbulence in pipe affect butterfly valves disc?

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Response 1: In most cases fluid flow should be calculated to operate at a Reynolds number within the range of turbulent flow. This does not effect the operation of the butterfly valve.

Question 5092: Is it necessary to keep 1.5D free run distance in upstream and down stream of valves? It is applicable for which type of valves.

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Response 1: This is not a requirement for valves.

Question 5093: What is the difference between y-type and t-type strainer? Y-type is usually used in small bores. What is the reason?

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Response 1: Size for size the T-type, or basket strainer, can accommodate more flow than a Y-strainer. Particularly when you get into flow rates above 150 GPM. Strainers are sized and specified based on fluid service, filtrate particle size, and pressure drop across the filter element. Y-strainers are installed with the strainer in the position range of down to horizontal. Cleaning them requires blowdown, or opening the strainer cap to access and pull the strainer. Any liquid in the strainer cavity will have to be drained. The basket strainer is generally installed with the strainer element up. Remove the cap and then remove the filter for cleaning or replacement. Y-strainers are generally selected for steam use for two reasons, the metallic particles it captures are relatively heavy and fall out nicely in the pocket formed with the strainer in the down position; and the size particles the Y-strainer is required to capture do not require a strainer in the micron filter element range.

Question 5094: A bout the cooling tower I have a question as below:
We have data as below:
-flow : 6048M3/h
-approach:5.5
-cold water :34.5 C
-hot water :49 C
-rated duty : 83 Million kCal/hr
-air wet bulb temp: 29
-five (5) X 25% cooling tower circulation pumps ( one as a spare) each with capacity of 1374m3/hr , P=9.7 bar

Please specify number of cells related cooling tower .

Please click here to offer your response. Reference Question #5094
Response 1: Refer to http://www.advantageengineering.com, http://www.coolingtechnology.com/, http://www.coolingtowersystems.com/, http://www.chillerdepot.com/, http://www.precisioncoolingtowers.com/, and http://www.waterchillingproducts.com/index.cfm/Cooling_Towers_. Provide them with the data and they will size your cooling tower requirement.

 

 



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