Very Slow Gas Leak...

[Zaq]

I have a combination CSST and black pipe gas line system and it has a small leak. At 15psi, it has only dropped 1 psi in a 6 day period. I'll continue to monitor it, but is this a real concern?

Thoughts? If I need to continue the search, thoughts? I'm unable to get bubbles, so any other alternative?

Thanks for your feedback

 

[Reach4]

I have a combination CSST and black pipe gas line system and it has a small leak. At 15psi, it has only dropped 1 psi in a 6 day period. I'll continue to monitor it, but is this a real concern?

The CSST may have relaxed a bit.
https://www.uponorpro.com/~/media/extranet/files/manuals/plu_pressuretest_is_08123.aspx?sc_lang=en discusses the effect with pex. I would think the same effect could happen with CSST.

If you now drop the pressure to 10, and then see the pressure rise, that would seem to confirm that.

There would also be temperature effects too. For that, record temperature when you record pressure. If the temperature was about the same at the time of the measurements, I expect you are seeing the relaxation effect.

 

[Sponsor]

 

[hj]

The "official test" is usually 15 minutrs at 10 psi, so there is no way I would worry about that "leak" if the is actually one.

 

[Sylvan]

First off when using a gauge to get proper reading such as low pressure natural gas the max pressure at the end of the scale would be 5 PSI and the actual test would be on the 3 PSI mark as all bourdon gauges are most accurate in the middle . Going to the very end will damage the gauge or the very least it has to be re calibrated on the more expensive types we use for boiler inspections
Second
There is something called pressure temperature relationship meaning the higher the ambient temperature the higher the pressure would be
This was more pronounced with the old Mercury gauges as we used a 6" column (3 PSI) but in the colder weather the mercury would drop ad like a thermometer when someone has fever the reading would be higher
The leak your talking about is so small I agree with HJ

By the way NYC changed the gas test to 3 PSI for 1/2 hr before it was 3 PSI for 10 minutes

Any pressure above 1/2 PSI in NYC is considered high pressure

 

[Jadnashua]

Hopefully, the line wasn't connected to any appliances during the test! A temperature difference (colder now) could easily account for that pressure change. Air pressure will change about 1-psi for a 10-degree F change.

 

[Jeff H Young]

10 psi 15 minutes. I think youre good