Codes or Norms governing double walled underground pipe

[DerekLJ]

Hi everybody,

We are building a thermal powerplant in Peru, where many oily-water drainage system is underground.

It has been suggested to us that all these tubes be double walled because they are always double walled in power plants in the US.

I understand that this is good engineering practice, but is there a standard or Code that demands that all underground oily water system piping be double walled?

I searched EPA, and was surprised to find that they didn't say anything about it.

If there is nothing that demands it, i would like to know WHY, this drainage piping is always double walled in the US, especially if it doesn't contain hydrocarbons, except for the oil in the oily water.

 

[metengr]

You mean double xx extra heavy???? Dbl EH is used in high pressure steam applications in thermal power plants, typically under ASME B31.1.

 

[DerekLJ]

No,i'm not talking about thickness. Double walled pipe can be any thickness. I'm talking about pipe with two walls, meaning an interior pipe inside of an exterior pipe. One inside the other.

After re-reading this post, i noticed that it may seem slightly sarcastic or harsh. That isn't the intention at all, i just don't know how else to explain it.

 

[Apakrat]

You may be referring to using smaller heavy wall pipe carrying contaminating substances installed in a larger thin wall pipe, intended as a casing to capture any leads occurring from the smaller transporting pipe.

Detections of any very small leaks are found early from the leaking heavy wall pipe and can be mended, replaced or whatever, before any damage, environmental or otherwise, is done.

At 74th year working on IR-One PhD from UHK - - -

 

[metengr]

It has been suggested to us that all these tubes be double walled because they are always double walled in power plants in the US.

I would guess your assumption is incorrect. I work for a Power Company in the US, we have no such requirement for a pipe within a pipe. This might have been specified by the AE firm that designed the BOP piping system.

 

[DerekLJ]

You may be referring to using smaller heavy wall pipe carrying contaminating substances installed in a larger thin wall pipe, intended as a casing to capture any leads occurring from the smaller transporting pipe.

Thats exactly what i'm referring to. Is there a standard or code that demands this type of piping in underground piping systems?

 

[vzeos]

This is covered in the Handbook of Double Containment Piping Systems by Christopher G Ziu.
See attached.

 

[Apakrat]

Don’t know if this will help, but in my design days, before the days of EPA, I gathered info from DOT (Dept. of Transportation),in the US State where the pipeline or plant was to be constructed, plus the Federal DOT and Mine Safety, (Bureau of Mines) people. Sometimes even when at power plants and water way earthen dams have had to use the cased system with design research via the US Army Corp. of Engineers and Bureau of Reclamation.

Just for amusement, I remember one code was one sentence of very fine print over 2 pages long, linked together by “,” “;” and “and” , etc. Quite evident of being written by a political lawyer without the common sense of realizing a pipe is fabricated with a hole through it.


At 74th year working on IR-One PhD from UHK - - -

 

[Apakrat]

Don’t know what You need in pipe sizes, pressures etc, did a little Internet searching and found–

http://www.usace.army.mil/publications/eng-manuals/em1110-1-4008/

which has a “ Double Containment Piping “ part at

http://www.usace.army.mil/publications/eng-manuals/em1110-1-4008/c-8.pdf

At 74th year working on IR-One PhD from UHK - - -

 

[rmw]

I have worked in and out of power plants for 40 years and I have never heard of a require or the use of double walled pipe for such an underground piping situation. I'd make whoever is binding that hogwash on you substantiate it.

rmw

 

[vpl]

DerekLJ

Here's a link to the EPA regulation for double-walled tanks & piping for underground storage tanks:

http://www.access.gpo.gov/nara/cfr/waisidx_08/40cfr280_08.html

However, I don't know why this requirement would apply to a project in Peru.

Haven't looked for Codes or Standards, but unless you're bound by it, does it matter if one exists?

Patricia Lougheed

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[BigInch]

That's about what I thought too, but wasn't sure about U.S. power plants built under the latest regulations. It seems like a very excessive reqirement for oil-water drains. We do not use double wall for pipeline pump station oily-water drains and I can't see any real difference between an OWD in a pump station or an OWD in a power plant.

**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[mauricestoker]

You may want to try looking at API standards. When the Leaking Undrground Storage Tank (LUST) legislation was being drafted in the mid 80's, very heavy influence was given to excluding the petroleum industry specifically from underground tank laws, and standard at that time was retention of 10% to include piping.
Nowadays, most of the UST program is implemented under State or local ordinance, so you should probably familiarize yourself with local national requirements and the API (if applicable). I've done several gas station and POL (Class III) sites, and that is the only place where I know double wall piping is required, and then only on suction side and manholes-as far as I know it does not specifically apply outside of UST, AST applications.
It is very useful as redundant protection against hazardous substance leakage protection where any known leak inside a facility could have catastrophic effects. I've recommended it for bio kill tank applications inside of facilities.

 

[DerekLJ]

However, I don't know why this requirement would apply to a project in Peru.

Haven't looked for Codes or Standards, but unless you're bound by it, does it matter if one exists?

The owner is an american company. Regardless, we always try to fulfil american standards in order to guarantee the work quality, even thought they may not "officialy" apply