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Corrosion Resistant Underground Pipe
2

Corrosion Resistant Underground Pipe

Corrosion Resistant Underground Pipe

(OP)
I just wanted to check if anyone had any ideas of what the new underground pipe treatment was to prevent corrosion.  I have to install a small amount of underground pipe and think cathodic protection might be overkill.

The only real pipe that I know to apply is carbon steel pipe with coal tar epoxy and a wrap with special joint coating and taping.

Anything else out there that I should be aware of that works better, is cheaper, etc.?

RE: Corrosion Resistant Underground Pipe

What is going in the pipe (and at what conditions)?  How big is the pipe? Why do you need to use carbon steel?  

RE: Corrosion Resistant Underground Pipe

(OP)
I was thinking CS because it's a short run underground.

I have a couple of pipes to install with a number of process fluids going through them:

- nat. gas (3")
- clean water (8")
- white water ( for paper machines ) (12")

Just looking for ideas...

I wasn't considering HDPE due to short length.  I just didn't know if there was some new pipe coating out there...

RE: Corrosion Resistant Underground Pipe

Fusion bonded epoxy coating may be an option.

Geoffrey D Stone FIMechE C.Eng;FIEust CP Eng
www.waterhammer.bigblog.com.au

RE: Corrosion Resistant Underground Pipe

Fiberspar linepipe is a good solution, at smaller diameters (4" typically) for natural gas, water, crude, etc.

http://www.fiberspar.com/news.htm

We are currently installing some. If you use a ditch witch, or plow, you can really install it fast.

"Do not worry about your problems with mathematics, I assure you mine are far greater."   
Albert Einstein
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RE: Corrosion Resistant Underground Pipe

Yes, Louie, I exactly remember time when protection you mention was dominant for underground piping.

However, technology is advancing almost every day... Depending of service function of your pipe, I beleive ductile iron is the best choice - manufacturesrs sell pipe for undergorund installation with surface protection included. Even sandfill requirements are not so strict as this pipe is really robust.

HDPE pipe also does the job - can be used for virtually anything: water, gas, sewer (only high temperature limitations apply).

sunshine

RE: Corrosion Resistant Underground Pipe

IF this is in the U.S.  I would be willing to bet that if you put coal tar in the ground today, they would want to have a long long talk with you

RE: Corrosion Resistant Underground Pipe

I mean The E.P.A. would like

RE: Corrosion Resistant Underground Pipe

ductile is probably your best bet. You can get it with an ashpaltic coating, and when wrapped in simple black 8mil plastic it lasts a long time. We are using it now for sewer service, nat gas, water, etc.

RE: Corrosion Resistant Underground Pipe

Fairly common in waterworks industry is DI as listed above or PVC pipe with DI fittings.  I don't know if PVC is compatible or usable with natural gas, though.

RE: Corrosion Resistant Underground Pipe

For short run you could cover your steel pipe with a protective tape. Denso comes to mind.

Kevin

RE: Corrosion Resistant Underground Pipe

What you should be aware of is that no coating is perfect and that corrosion will occur at breakdowns in the coating. Cathodic protection will provide a back up to minimise corrosion at these breakdowns.  So, the need for cathodic protection should be based on a risk assessment of how much corrosion will occur, how quickly it will occur, and what are the consequences of a breach in the pipe.  Also, take into account possible interference from neighbouring buried structures that may already have CP.

Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdo/

RE: Corrosion Resistant Underground Pipe

(OP)
Well, how about I compound the problem...

In this same area, I need to relocate some process sewer lines...

One line coveys waste with a PH = 2.0, the other two lines carry waste with a PH = 10.5.  HDPE should be a no brainer, but the waste temperatures can reach 150-160.

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