Selecting materials for piping systems

[Thomasjl]

My position is Mechanical Piping Engineer in the (Bio, Petro) Chemical industry. My skills are running short with determining the composition of materials for piping and its components. For example: you have a pipe transporting a certain medium (sea water or chloride etc.), then my problem is: what type of materials do I choose for the pipe, valves, gaskets, bolts, etc. Other examples are: the material composition of a valve is specified in a company specification; now this valve is not in stock but there are lookalikes; then they ask me whether these other materials also satisfy. The same counts for a valve that already is supplied and does not meet the specified materials, is it good enough or is it to be send back. I can’t answer these questions properly.
I can’t describe exactly where I am looking for because I don’t know what is available in this field. It is rather specialistic and can be anything: book, essay, tables, index, reference work or ?.

Thanks for helping me.

 

[yhisus]

Thomasjl, try getting ASME B31.X (where X are natural numbers). All these codes will give you some information about several piping systems and how to design it.

I hope this post serves you to begining your search.

 

[MJCronin]

I respectfully disagree with yhisus.....

The ASME B31.X codes will tell you which piping materials are acceptable for the code, but will not tell you which materials are acceptable for a certain application.

Thomasjl, unfortunately, you are at the tip of the spear. Your impossible situation is certainly not your fault and you are the resultant of a long string of poor management decisions and cost cutting that has resulted in:

- Dismissal of all senoir staff in "Corporate Engineering"

- Heavy reliance on technical expertise of vendors

- MBA assumption that any engineer is as good as another

- Frenzied re-hiring of select retirees

- Quickly thrown together "mentoring programs"

- Risky reliance on internet advice from strangers

I feel that if you were working for an organized, reasonable company, you would have either company developed piping "line specifications" or senior engineerin staff to consult with.....

Line specifications typically describe and authorize certain piping, gasket and valve materials for a partiular chemical at various pressures and temperatures.....this is what you need

-MJC

Instead, you are put into a bad position with no resources.

To answer your questions

 

[Thomasjl]

Thanks MJC,

My position is not that bad, it doesn't occur every day and I am not expected to know everything. I do have other people I can fall back on, but it takes time and efford. But above all: I hate black holes in my knowledge, specially when the answers seems to be within reach.

MJC, it looks like you know what I need, but where can I find it?

Thanks, Thomas

 

[SJones]

For some self help development, start by looking at NORSOK M-001 to get a feel for piping materials selection. Then look at NORSOK M-630 for the piping data sheets that detail the purchasing requirements for the piping items.

http://www.standard.no/en/sectors/Petroleum/NORSOK-Standard-Categories/M-Material/

Regarding non-compliant materials, that is a bit special and, if you do not have the competence, you should not be in the position of having to judge suitability. The company should have a management of change process to be followed which ensures that competent people assess the safety implications of accepting non-compliant materials.

http://www.hse.gov.uk/comah/sragtech/techmeasplantmod.htm

http://www.hse.gov.uk/comah/sragtech/techmeaspipework.htm

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[MikeMet]

For getting data on material compatibility, a good reference is the NACE Corrosion Data Survey. You can find what materials are appropriate for hundreds and hundreds of processes. You can also look at the website for all the materials suppliers, such as Alleghney Ludlum, Sandvik, Special Metals, etc. most have materia compatibility information.

Gasket selection can be found in information from gasket suppliers. Same for casting data, go to Flowserve website for good compatibility information.

Of course never rely on one source and you will always find gaps where there is little to no data for a process.

If all else fails, hire a materials consultant.

 

[MJCronin]

Another good source is the "Piping Handbook" by Nayar.

For specialty or bulk chemicals, I would consult the supplier, who usually has developed a handling guideline for the particular chemical.

Here is an example:

http://www.sschemical.com/handling.php#

-MJC