natural gas line pressure test

[Cascadian]

Hi all,

For a final check (inspection is coming soon), my gas pipe was pumped up to 15 PSI. Over two weeks the gauge has dropped to around 6.5 PSI. When I checked the first night it was still right at 15, and I think (?) a day or two later as well. Then I didn't check it so often. 2 days ago it was at 7.5 PSI. With such a slow leak I'm sure that it will still pass inspection (around here it just has to hold pressure for 15 minutes), but should I be concerned at all? Or is it probably not even the lines but the cheap gauge causing the slow trickle?

Thanks!

[second opinion]

[QUOTE=Cascadian;13983001]Hi all,

For a final check (inspection is coming soon), my gas pipe was pumped up to 15 PSI. Over two weeks the gauge has dropped to around 6.5 PSI. When I checked the first night it was still right at 15, and I think (?) a day or two later as well. Then I didn't check it so often. 2 days ago it was at 7.5 PSI. With such a slow leak I'm sure that it will still pass inspection (around here it just has to hold pressure for 15 minutes), but should I be concerned at all? Or is it probably not even the lines but the cheap gauge causing the slow trickle?

Thanks![/QUOTE

Soap each joint and fitting

[OldSchoolMech]

It's leaking fix it ! Pump it back up and do a soap test.

Or leave it and make sure you tell the inspector about your leak

[motoguy128]

My plumber has told me of one case where he couldn't find the leak with soap. The leak was a tiny void in the cast fitting. An elbow I think. I think he started taking pipe apart and capping a section and working back until it would hold pressure. This was the only tiem it ever happened to him. But he's only been a master plumber for maybe 15 years.

[Southern Mech]

Let it fail inspection and let contractor make repairs, if it passes you may get stuck with a leaking gas line. It will all be documented for future this way

[second opinion]

My plumber has told me of one case where he couldn't find the leak with soap. The leak was a tiny void in the cast fitting. An elbow I think. I think he started taking pipe apart and capping a section and working back until it would hold pressure. This was the only tiem it ever happened to him. But he's only been a master plumber for maybe 15 years.

Thus the reason for checking each joint and fitting. If the right leak solution is used and low pressure the bubbles will form a honeycomb effect and increase in size, then rinse once leak has been found.

[Joehvac25]

Could be the temperature. Pretty hard to get leaks in gas pipe but it happens.

[skippedover]

When is a leak a leak or not a leak? Our gas code calls for new work in a residential application (.5 psi) test to be 3 psig for 10 minutes with no loss. In fact, gas cocks has a legal leak rate so expecting a system to test for 7-days with zero pressure loss is expecting more than can normally be delivered. Any leak that fails 3 psig within 10-minutes is definitely a leak to be located and repaired. BTB, existing work is tested at 1.5-psig!!

[t527ed]

leak should be found and repaired.
i just went back to a gas line i installed 3 weeks ago to remove pressure test and hook line up to furnace.
had 15 psi when i put it on and 15 psi 3 weeks later.

[Southern Mech]

leak should be found and repaired.
i just went back to a gas line i installed 3 weeks ago to remove pressure test and hook line up to furnace.
had 15 psi when i put it on and 15 psi 3 weeks later.

My parents just bought a forclosed house built in 03'. Only had gas logs and never a bottle hooked up. Still has 15 psig on the gauge 6 yrs later. Just so happens I was the contractor on the house for hvac and gas. I am asking for a raise in the morning

[etbrown4]

A leak is a leak.

Inspectors in our area require 30 psi holding for 24 hours. Lose 1 psi and you flunk!

Typical cause is either insufficiently tightened threaded joints or teflon tape not working to seal cheap Chinese threads. On the professional plumbing forums you will see lots of reports of problems with these new threads.

Best solution we've found is forget about teflon and use the Rectorseal white putty. Never had a leak with it. Have seen cases with these cheap Chinese threads where it took 8 wraps of teflon to plug leaking threads which were super tightened.

[Joehvac25]

We use rector seal, the yellow slop, #5 I'f I remember right. Teflon is against gas code I thought? 15 psi should be easy to hold, it's Probably a minor issue someone forgot to tighten something maybe.