Gas line integrity based on?

[fostercontractors]

I have 40lf of 1.25" natural gas line and I've developed a slightly rough idle on my natural gas stand by generator. My gas line is underground -it's yellow poly with risers /valves on either end, passed pressure test and inspection when we put it down in 2022 and about 6 mo after is when I started noticing the rough idle. The generator company has replaced the engine and a number of other parts to no avail -it still doesn't have a smooth idle. I'm concerned that I may have developed a tiny leak in my underground line even as the gas utility says I'm all good! They measure gas purity at 100% at the generator and said my piping system holds 4oz of pressure w/o any deviation at the meter. They also tested for purity at my gas range and water heater -all good.

Is it possible that my generator pulls air through the poly-to-riser connections when it's running even though the utility says it's holding pressure correctly? I can see my liquid moving up and down the slightest bit in my manometer while it's running and it's in time with the not so smooth engine rpms.

Should I break the gas line loose from the system and pressure test it?

 

[Slomoola]

I have 40lf of 1.25" natural gas line and I've developed a slightly rough idle on my natural gas stand by generator. My gas line is underground -it's yellow poly with risers /valves on either end, passed pressure test and inspection when we put it down in 2022 and about 6 mo after is when I started noticing the rough idle. The generator company has replaced the engine and a number of other parts to no avail -it still doesn't have a smooth idle. I'm concerned that I may have developed a tiny leak in my underground line even as the gas utility says I'm all good! They measure gas purity at 100% at the generator and said my piping system holds 4oz of pressure w/o any deviation at the meter. They also tested for purity at my gas range and water heater -all good.

Is it possible that my generator pulls air through the poly-to-riser connections when it's running even though the utility says it's holding pressure correctly? I can see my liquid moving up and down the slightest bit in my manometer while it's running and it's in time with the not so smooth engine rpms.

Should I break the gas line loose from the system and pressure test it?

You need to fire ALL gas devices, everything in the house, THEN measure your input pressure.

If your hot water tank is not firing and say you have a cook top, they all draw gas on demand.

Is your regulator large enough to support your genny with the rest of the gas items?

Your gas company tested the gas. Why are you still questioning their readings?

Where did you get the gas from for the generator? T off the water heater for example? Rob from the gas furnace if you have one?

 

[Sponsor]

 

[Slomoola]

Why don't you slightly open the carb jets if your genny has a carb? Can't believe the genny company has been out along with the gas company. Your genny regulator sounds flaky to me. Not letting enough volume/pressure to the genny.

How does the genny meter the gas into the engine? Carb, fuel injection or regulator?

 

[Jeff H Young]

its not a leak . generator coompany replaced parts for a reason coulda been just a hunch. maybe they didnt change the right part . likely a carb but it could be ignition I cant guarantee I just dont suspect its a fuel issue unless no one knows what they are doing with the gas co . try a whole new Genny see if that fixes it assuming its under warranty