Pneumatic Test 1

[mcm1209]

Guys
I am working for a pipeline construction company.
I have been in the process and pipeline services since 1999.

I joined this company to start a hydrotest division.
We are being asked by our customer to conduct a pneumatic test of 7 miles of 20" pipeline.
Test pressure is somewhere in the neighborhood of 1300 psi.

I am very opposed to this but my company wants to push forward. The customer has given us the green light.

Oh yeah
We are doing this test within the week.

I need hard facts to stop my company from doing this. I have been looking for info on the net but have not been able to find something concrete.Or facts so i feel better about this.

I did find
"437.4.3 Only allowed for piping systems operated at 20% or less of SMYS"

Need help

 

[dcasto]

my two cents, we had an engineer sold on the no pneumatic test religion. so he tested the plant with water. It was a cryogenic plant. He lost 2 weeks production because he froze the plant up upon start up. He almost lost the 35 week delivery platefin exchanger to.

I've got a dozen cryo plant N2 test under my belt, no incidents, no freeze ups.

 

[weldstan]

Had a high pressure 30" X-60 gas line installed through populated areas and under a main Blvd of L.A. once. One pipe failure in the long seam during hydrotest at pressures exerting < 60% of SMYS. If pneumatic testing was performed, the event would definitely had made the nightly news.

We routinely pneumatic test 12" seamless fuel gas piping at 660+ psi at new powerplant installations but tests are thoroughly evaluated, specific procedures written with safety issues paramount. Fill lines must be tested, pressure relief valves installed, etc. Have not had any safety related, catastrophic incident in the 17 years of my review/involvement.

Additional pneumatic test considerations are:
1. Pipe manufacture -seamless, sub arc welded or ERW
2. Pipe manufacturer (China??)
3. Pipe testing by manufacturer witnessed by Purchaser
4. Other inspections made by Purchaser
5. Mode of transportation

 

[BigInch]

I'm glad things have worked out well for you.
Under well controlled access, probably behind locked fences and manned guard post entry permits much of the risk can be at least limited to company facilities and personnel.
Pipeline layouts are somewhat different.
And... Pneumatic tests are not allowed at all under B31.4

Independent events are seldomly independent.

 

[weldstan]

BigInch,
And done on a weekend with only the defined test personnel permitted on the site.

 

[BigInch]

Even better.

Independent events are seldomly independent.