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:
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.
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?
The tubing "fails" at elbows, in the middle of straight runs, seemingly at just random locations.
Well water; potable & process cold water; hot & cold soft water
60 - 75#
Cold water 55-65 F, hot water 75 - 140 F
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
< 5 fps cold water systems; < 4 fps hot water systems
Located throughout the system
No
Operating equipment
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
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..
 | MIT, Pune, India |
| VIT, Pune , India |
| Trinity Institute, Pune, India |
| Elixir institute, Thane, India |
| Suvidya 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 #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.
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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.
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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.
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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?
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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.
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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?
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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?
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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?
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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?
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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.
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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.
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
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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.
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.
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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
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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
hav