Maximum Chloride Content for test water

[PipelineDeptTME]

Dear Friends,

does anyone of you know what is the maximum chloride content for test water for Carbon and low alloy steel piping? On the web I found one paper which states 30 ppm, but I would prefer code/standard reference if possible.

Thank you

 

[XL83NL]

ASME PCC-2 provides soms guidance on this; 50 ppm for stainless steels

 

[stanweld]

You will not find it in B31.1, B31.3, B31.4, B31.8, etc. I have seen a number of Owner/Engr specs that limit chlorides to 500 ppm in hydrotest water for carbon and low alloy steel pipe systems.

 

[PipelineDeptTME]

I found what I was looking for. Check this:

DEP 74.00.10.10

Max Chloride content shall be 250 ppm.

 

[Latexman]

Our company spec goes a little bit further. "Liquids used to test austenitic stainless steel piping shall have a chloride ion content not greater than 250 PPM. The test liquid shall not be left in contact with austenitic stainless steel for more than 72 hours."

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[LittleInch]

For Stainless Steels I agree you need a limit, but seawater is commonly used in offshore pipelines with suitable oxygen scavanegers and biocides to reduce corroison and microbial action to a level suitable for hydrotest. Sometimes inhibited seawater can remain in there for some weeks before the pipeline is cleared and commissioned.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[BigInch]

Exactly LittleInch!
DEP strikes again!
If DEPs are not your job spec, toss them.
Fresh water (typical city water in United States) < 100 ppm
EPA recommended limits are 500 ppm
In other words, you can't taste that 30 ppm salt content!
Sea water contains 30,000 ppm
I've left 100s of miles of subsea pipeline with saltwater hydrotest inside for up to 6 months. 30 years later, still flowing gas.

Independent events are seldomly independent.

 

[stanweld]

Also agree with LittleInch and BigInch. Where fresh water is at a premium or essentially unobtainable, sea water and brackish water have often been used without damaging the pipe system.

Colorado River Water can be over 1000 ppm Chloride.

 

[Latexman]

The OP didn't say anything about the service or normal operating temperature. Some of my SS pipes normally run at elevated temperature. If seawater was used to hydro a gas line, then it was drained and dried, and run at 150-200 F, would that be okay?

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[BigInch]

SS has an issue with chloride stress corrosion cracking, especially 304. 316 and others are not immune. SSC potential increases with temperature and can occur in low O2 environments, areas of increased stress (residual weld stresses), strain rate and cold work. Post weld heat treatment is often recommended. It is not dependent on water content, so it doesn't matter if temperatures are over 212F, and in fact SSC potential still increases. It has been known to occur at low temperatures as well.

Simple draining and drying might not have removed the salt, possibly leaving concentrated salt deposits near welds and seams. Were the lines pigged and flushed with fresh water before drying? Was the resulting salt content of the fresh water tested for chloride content?

Independent events are seldomly independent.

 

[LittleInch]

The OP also refers to low carbon or alloy pipe, not SS, where I agree with other posters and personally I would not use any water not classifies as "potable".

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[BigInch]

Right. CS and SS have very different chloride envelopes. Don't X them up.

Independent events are seldomly independent.

 

[SJones]

Which is exactly what the OP has done when looking at the DEP. The said DEP states:

"Equipment manufactured from carbon steel or low-alloy steel may be hydrostatically tested
with potable, brackish or salt water as available. If potable water is not used, the test water
shall be completely drained and the equipment flushed with potable water immediately after
testing and thoroughly dried with hot air or steam."

Steve Jones
Corrosion Management Consultant

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

All answers are personal opinions only and are in no way connected with any employer.

 

[Latexman]

Oops! I did mentally jump from low alloy steel into SS. My bad!

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[BigInch]

I jumped to conclusions with the DEP then.
DEPs I apologize.. just this once.
Actually they're not all that bad, when used correctly.

Independent events are seldomly independent.