New pipeline engineer 1

[csr17]

Hey guys,

I've been reading this site for the past several months but this is my first time posting. I'm a young engineer with about 2.5 years of experience and just got a new position with an EPC firm involved with pipeline design.

At my previous job I was doing applications engineering for a manufacturing firm that sold high pressure piping for saturated/superheated water and steam applications (power plants, pulp and paper mills, etc.). I'm familiar with ASME Sections I, II, IX, ASME B31.1 and some of ASME B16 on flanges, valves, and fittings. I worked with only seamless pipe and most of it was pretty small (2.5" NPS or smaller) so we used mostly socket welds. I am familiar with butt welds and NPT connections as well. Most of the steel I used was SA-106 GRB and SA-105. Occasionally used stainless and nickel-chrome-moly for high temperature applications. I am familiar with NDT, PMI, hydro tests, mill certs, so on and so forth.

With my new position, I'll be working on pipeline design, compressor stations, pig launchers/receivers, and so on. I have done some reading on the basics but have no technical knowledge other than what I described above. I am very excited and interested to start the new position and I am trying to get myself familiar with the material, so I have a few questions:

1. What pressures are typical? Previously, I was working with pressure up to 3000 psi so I am used to using high pressure class fittings (1500#, 2500#) and thick pipes (Sch 80, 160, XXH). It is my understanding that pipelines are typically much lower - around class 600?

2. Which steels are typical? Like I said above, I have mostly used SA-106 GRB carbon steel. What else should I expect to encounter? Are materials other than steel sometimes used?

3. Which design codes are typical? I believe I will be using B31.3 and API. I am aware of both but have never used them.

4. What are some different factors to consider now that I'm dealing with oil/gas instead of water/steam? Things like corrosion allowances, temperature/pressure ranges, etc.

5. What are some good websites and publications to read to keep up to date with the industry? I like to stay informed.

6. Any other words of wisdom or cautionary tales for a young engineer about to start working with pipelines?

I know this is a big post but I'd really appreciate any info you could give me.

Thanks

 

[LittleInch]

CSR17,

First off welcome to the forum and to a potential pipeline engineer - it's great to see such enthusiasm out there.

That is some list and I know of courses that last 4 or 5 days to go over that. It might well be the best thing to try and get yourself on one of these to get a really good foothold and start to understand what you don't know...

First off some basics. There is a difference between piping (what you have been doing) and pipeline, both in design, construction, materials and general way of thinking. Don't confuse the two....
Also pipeline engineering in particular, the codes are basic design rules and don't try to be very prescriptive. There are simply too many variables to cover all things.
Your company way well have one way of doing something or sets of "standard" designs, but that doesn't mean that is the only way it is or can be done.

Ok your questions
1) In transmission pipeline systems, it will vary, but yes not usually much more than #600 or #900 rating and distribution systems are much lower. Oil field design on the other hand can go to class 2500 and beyond. Pipeline wall thickness tends to be described in thickness, not by piping schedule. 0.5" / 12.7mm +/- 1/4" would often cover a lot of pipelines.

2) Pipeline steel is normally API 5L, grade (strength) to be determined by the designer. In recent times X60 (L415) had become a default grade, with X70 becoming more common. The baseline is Grade B (35,000 psi SMYS) which is also quite common, especially for low pressure applications where you don't need the high strength material. This is directly applicable to A106. other materials - Yes you see PE, fibreglass or GRE/GRP, FRP is becoming more common, but all wrapped up probably < 5% of pipelines other than low pressure water or gas are made from things other than some sort of steel. Most pipe above 8-10" will be seam welded in some way shape or form - let the materials guys sort that out....

3) Design codes for pipelines can vary depending on where you are. US /middle East - ASME B 31.4 (liquid) and B 31.8 (gas) predominate. ISO 13623 is slowly gaining hold in certain locations and in Europe other country codes apply. PD 8010 is quite a decent design code and has a lot of examples, AS 2885 applies in Australia and there is a Canadian code I've never used. you need to know which one applies and what the individual country legislation overrides it - the US has the CFR regs and many other countries have their own legislation. API codes and standards you often see in wellheads and oilfield systems.

4) All those things. also understand how bad it is if any of the contents start to leak out or rupture. Steam isn't great, but water / steam won't explode or catch fire. difficult to answer that one in a single line....

5) this website is good, engineering toolbox is quite good, try looking at this and download the guides - they are very useful and are some excellent reading, especially if you're working for an EPC contractor.

http://iploca.com/page/content/index.asp?MenuID=319&ID=820&Menu=1&Item=28.13.1

There are free magazines available electronically - World pipelines springs to mind, just sign up and get it sent automatically

6) As someone else said recently, there's no such thing as a stupid question, but just choose your place and person to ask. The middle of a meeting with the client isn't the place to demonstrate that you don't understand something....

There are a limited number of rules

There are lots and lots of acronyms and abbreviations - don't assume you know what they are - ask

There are lots of people who will claim something is as it is because it is "in the code". Often it isn't - Know and read your codes so you can respond with actual wording, not what someone thinks it said. Codes do change over time - make sure you're using the latest edition - it is very easy to check online.

Many designs are just "custom and practice"

Look and learn then apply your learning to the next project

There is no such thing as a wasted site visit

See some construction and commissioning in practice, even if it's in the middle of nowhere - it is invaluable to understand what is easy in practice and what is difficult / dangerous

Ask questions here and also respond to posts - you might find you know something others don't

Get yourself on a decent couple of courses

Have fun and hope this helps

LI


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[BigInch]

For pipelines designed for the USA start here,
Federal Law, Code of Federal Regulations (CFRs)
Title 49 Part 192 Gas Pipelines
Title 49 Part 195 Liquids Pipelines
Title 49 Part 193 LNG Facilities
Title 49 Part 194 Emergency Response Planning for Onshore Pipelines
Those generally cover all but remote gathering systems.

Other USA-centric pipeline Design Specs, which are also commonly used over much of the world.
ASME B31.4 Liquid Hydrocarbon Pipelines
ASME B31.8 Gas Transmission Pipelines
Federal Law takes precedence and does not reference the latest issues of these codes (older version applies).

Pipeline and Hazardous Materials Safety Administration

http://www.phmsa.dot.gov

State and local regulations apply, such as

http://www.rrc.state.tx.us/

California Public Utilities Commission

http://www.cpuc.ca.gov/puc/

http://www.ncuc.commerce.state.nc.us/ncrules/rulstoc.htm

http://www.dps.ny.gov/

Some of which have additional design requirements, but most are only concerned with setting rates and tariffs.
Public Street & Roads, or Highway Authorities, City, County, State and Federal for Crossing regulations and requirements
American Petroleum Institute has numerous standards
API 5L for pipeline pipe, etc.

Stay Safe!

 

[csr17]

Thanks guys, much appreciated. I will certainly look into those resources you provided.

If you don't mind, I have a few more questions - pretty basic I think:

1. How is the size/capacity of a pipeline specified? I assume it is volumetric flow rate? Or something else? What would be considered a "big" pipeline? Is there some quantity analogous to a power plant's capacity factor that describes how much product the pipeline has delivered versus what it was capable of delivering over time?

2. With regards to pigging: I understand there are a number of different pig designs which are used to do a number of different things (maintenance, data collection). Is there a standard which defines minimum pigging requirements, such as type of pigging, frequency, and number of pig stations per line length? Or is it more open-ended and depends entirely on the preferences of the owner?

3. My old piping job involved a bit of instrumentation and electronics, so I am familiar with NEC hazardous areas (Class 1 Div 1 etc). I assume that classified hazardous areas are common in pipeline facilities? Perhaps not outdoors but inside compressor stations etc?

Again, thanks for the help. I am the type who understands finer technical details better after I know the crude basics - so I'm trying to prepare myself as best as possible.

 

[bimr]

Your questions are not basic.

1. The pipeline is specified for the process conditions.

http://www.eng-tips.com/viewthread.cfm?qid=383122

The size of the pipe and what is "big" depends on what industry that you are working in.

Pipelines are designed to operate within a flow range. The upper flow range is determined by the economical pumping rate. Too high of a flow rate means too much frictional head loss (more power to pump in cf fluid pumped/power unit). The lower limit in the flow range is determined by a number of factors such as sediment in the pipeline, air entrainment, etc.

2. Pigging has to do with the preferences of the owner and the liquid that you are pumping. Some liquids do not require pigging.

3. Hazardous classifications depend on what you are pumping. Water does not require hazardous areas, but flammable liquids will require hazardous area classifications. Some areas out of doors are classified, it depends.

 

[LittleInch]

csr17,

don't worry. Remember that a lot of pipeline design is not codifed or laid down as the variables are too great to do this.

1) Size is normally OD in nominal inch size..., Capacity units can vary depending on how the client views it. Liquids is usually volume (m3/hr, bbls/day, GPM etc), sometimes weight (million tonnes per year). Gas is standard volume - scf/day or scm/day is quite common.

Very similar calculation - often call up time or reliability, but in practice you normally you can't get much better than 90-95% over a year for actual throughput versus nominal maximum throughput.

If I were to classify pipelines for hydrocarbon transmission systems I would get
S - <=12" OD
M 14"-30"
L 32" to 42"
XL > 42"

If you're talking water transmission you could probably double those sizes for the same classification.
If you're talking local utility distribution maybe half of those sizes.

2) Is there a standard that defines what you have listed - no. there may be individual company recommendations, but the requirement and frequency / length is very different for each system. Normally onshore you end up with a pump or compressor station every 250-300km or less and most pigs will normally go that far so no need for extra facilities unless the client wants them.

3) Hazardous area calculations and areas are the same for any plant wherever it is. Pipelines per se have no hazardous area, like piping, unless you have a flange, fitting, valve, relief valve, vent etc. The electrical hazardous area calcs are the same for piping and pipeline facilities.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TensionvsTorque]

I have worked on a substantial amount of LNG, Compressor Station Builds, Pipeline projects, etc.

ASME-PCC-1 is a very nice read.

Feel Free to bounce thoughts off on me email HYTORCMD at GMAIL dot com

In regards to flange assembly I recommend use of a through hardened washer to control friction surfaces, increase grip length, etc. I also recommend using 4 tools at parallel to achieve as ASME refers to Parallel Joint Closure.

The company I work for is HYTORC. They came up with a very nice system for flange assembly that eliminates bolt side loading, saves up to 80% time on flange assembly, and makes the job hands free which eliminates chance of finger pinch as well as reduces chance of stress/strain to operators.