Any problem with threaded connection on H2S service under low pressure?
Any problem with threaded connection on H2S service under low pressure?
(OP)
Hi,
This is grade B piping (SA 106B, and SA 105B fittings)in oil/gas service on well sites. H2S can range from 10ppm to 10,000ppm, and pressure ranges from atmospheric to 300psig. My questions are:
1. will there be any issues with threaded connections?
2. I know welding is preferred, but are there pressure and H2S conditions that can make threading (when done properly)an issue?
This is grade B piping (SA 106B, and SA 105B fittings)in oil/gas service on well sites. H2S can range from 10ppm to 10,000ppm, and pressure ranges from atmospheric to 300psig. My questions are:
1. will there be any issues with threaded connections?
2. I know welding is preferred, but are there pressure and H2S conditions that can make threading (when done properly)an issue?
As much as possible, do it right the first time...





RE: Any problem with threaded connection on H2S service under low pressure?
The simple fact that 'threading' is incorporated in ISO 15156-2 means that some people, at least, don't see a problem with it. Some others do find a problem with the propensity to initiate corrosion and the stresses that may promote cracking.
Who is right?
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.
RE: Any problem with threaded connection on H2S service under low pressure?
That is the essence of the issue. I'm one of those people who have successfully used NPT threads (and machine threads with careful selection of o-ring material) in H2S service. I've stopped spec'ing them. Far too many company spec books absolutely prohibit threads in H2S service. Fighting the battle with people who would rather have a policy than an analysis is just beyond my capabilities.
If your company allows threads in this service, your success will be increased if you stay with pipe 2-inch and smaller (I've had a lot of trouble getting field crews to consistently torque 3-inch and 4-inch properly at the end of the day) and find a pipe dope that the manufacturer has tested in H2S service.
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Any problem with threaded connection on H2S service under low pressure?
RE: Any problem with threaded connection on H2S service under low pressure?
Failure of engineers to do engineering properly was the problem. I will never stop being shocked by the amount of "engineering by wishful thinking" that goes on in Oil & Gas.
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Any problem with threaded connection on H2S service under low pressure?
even though such a fools errand it would be.
RE: Any problem with threaded connection on H2S service under low pressure?
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Any problem with threaded connection on H2S service under low pressure?
RE: Any problem with threaded connection on H2S service under low pressure?