water quality for pipeline hydrotest

[bo7winner]

Hi all,

water analysis result shows sulfate content 900 ppm which is inconsistent with company specification,I am asked to submit the deviation to release pipeline for hydo- test:.
a)is any standard for hydro test water quality acceptance criteria?
b) shall I add biocide & which type to avoid corrosion?
please help me.
bo7winner

 

[bimr]

This was just discussed in another forum:

hydrotest water quality

The secondary standard for sulfate is 250 mg/L. The secondary standard for TDS is 500 mg/L.

EPA has established National Secondary Drinking Water Regulations (NSDWRs) that set non-mandatory water quality standards for 15 contaminants. EPA does not enforce these "secondary maximum contaminant levels" (SMCLs). They are established as guidelines to assist public water systems in managing their drinking water for aesthetic considerations, such as taste, color, and odor. These contaminants are not considered to present a risk to human health at the SMCL.

 

[racookpe1978]

A one-time excess sulphates injection of static fresh water into a oil pipeline could be argued as "inconsequential" because the test water won't be in the pipeline very long, and the actual process fluid is going to flush and then re-wipe the walls with its peculiar sulfate-oil-mixed chemical residues for many years. "Drinking" water is NOT pipe line test water. Further, the water hydrotest pressure will be high, but not so high as to "force" or "inject" the water into the pipe walls to begin future corrosion (like chloride stress corrosion initiation in a super-high pressure case for stainless steel.)

But you must address that specific concern as a line item in the report.

Disposal of the high-sulphate water after the hydrotest needs to be addressed as well: Will it be legal to "pump into the creek"? Surely it won't go in the sewer system near the test point, pipe end points.

 

[Dhurjati Sen]

Dear bo7winner,

Very difficult to close the NC. Go for potable water instead to avoid unnecessary paperwork.

You may not visualize now, but any future corrosion could be wrongly co-related with the hydro-test.

Regards.

DHURJATI SEN

 

[cvg]

make sure your water discharge (if it is going into waters of the US) meets the local requirements for De-Minimis permit. for example:

https://legacy.azdeq.gov/environ/water/permits/download/final_dmgp_2016.pdf