Okay to use a union at the meter? - Fixing EXTREMELY slow leak after a pressure test..

Amodedude1

Is it okay to put either a ground joint union or LR Union at my gas meter in order to fix a gas leak I discovered after a pressure test?

I had a new combo boiler installed which required re-piping the gas lines. The previous plumber (who I won't be hiring again due to several issues not just this) did not test the lines *before* taking everything apart. I went in after him to test the work and I pressure tested the lines and found a leak on the old pipework (not any of the new stuff he put in thankfully). 

I dropped my meter, connected my gauge from there and tested first at 15psi. It PASSED the 15psi for 30min test but dropped 1/2 psi after 24hrs. This was an EXTREAMLY slow leak but a leak none the less. 

In order to find the leak I had to use Cal-Blue and crank up the pressure to 40psi. Also, all equipment was disconnected and capped at the appliance with any valves in the open position. 

So now I'm wondering, since I am now fairly certain the new work is solid, can I just cut out the old work which is after the meter and use a union of some type (either ground joint or LR) to replace the old stuff? Or does the meter bar come apart near where my gauge is connected?




Don't seem to have a pic of where the plumber connected the old pipe to the new pipe but above may give a general idea my setup.

*Disclaimer* - I am well aware of the impacts of performing my own natural gas work. All work is to be pressure tested by a licensed master plumber in my area and inspected by the city. It IS legal to do my own work so long as I pull permits, follow the codebook, get inspections, test myself for sanity, test again by a trained professional and maybe follow some common sense. Ia'm just here looking for advice!

Amodedude1

And also, yes, I tested the gauge prior so I know the gauge wasn't the issue. The cal-blue gave a very positive leak at the old 90deg fitting. All other fittings did not bubble at all.

Also, yes, my gas has been shut off (by the utility with a lock prior to any work being performed...

mattmia2

You should check your specific code, but usually unions are allowed wherever they are accessible.

PC7060

Testing for long period will often indicate slight leaks such as you indicated. I've found that the test gauges are often the source.

Amodedude1

@PC7060 , yeah absolutely. I was very suspect of my el'cheapo homeflex HomeDepot gauge even though I had already tested the homeflex.  I repeated the test @ 30psi over the weekend using a new Winters Gauge and had the same results. That's when I picked up some of the Cal-Blue and pumped it up to 40psi. Really impressed with that stuff. I tried the Oatley leak detection fluid solution from HD and it didn't do anything. The Cal-blue is very thick and pin pointed even this tiny little leak with ease. 

Also, I agree, with a leak this small and the fact that I'm testing at over 80times normal operating pressure, it's hard to believe it would be an issue at 1/2psi but better to fix it just to be safe rather than have this keep me up at night or worse! 


@mattmia2 Yeah that's kinda what I thought, codebook says "a union shall be provided for all appliances connected by rigid pipe" but wasn't sure about the meter. I'll keep digging to see if it says anything...

Also, this gives me an opertinity to add a nice new 1" meter shutoff valve (on my side of the meter) so I can easily shut off the gas to the house without dealing with the 100+ year old meter bar from the ages of incandescent gas lanterns! 😬

EBEBRATT-Ed

@Amodedude1

I wouldn't be too hard on the plumber. When you install new gas pipe your not required to test existing pipe. It is assumed to be good unless it's rusted or someone smells gas.

Your testing at 15psi which is like 30x the highest pressure your pipe will ever see. At 1/2 a psi you wouldn't have a leak. + as you mentioned you had to go to 40 psi to find the leak. Put enough pressure on threaded pipe and it will leak although I have tested at 100 psi on some jobs

And yes, you can use a ground joint union.

ch4man

you said.

*Disclaimer* - I am well aware of the impacts of performing my own natural gas work. All work is to be pressure tested by a licensed master plumber in my area and inspected by the city. It IS legal to do my own work so long as I pull permits, follow the codebook, get inspections, test myself for sanity, test again by a trained professional and maybe follow some common sense. Ia'm just here looking for advice!

I say
you should call and ask your gas utility if they're ok with someone who is not qualified under the Operator Qualifications of CFR 192... working on their owned equipment?

ask your licensed master plumber if he is OQ'd

kevink1955

Check the large fitting at the meter bar, it just may be a swivel fitting that turns in the bar and will act as a union

dopey27177

If you are using unions on the gas piping (if legal or acceptable by the gas company)I made a practice of using a center punch on the collar nut of the union, reason over the years vibrations may cause the union
to loosen slightly and cause a gas leak.

I come from NYC where both Con Ed and Brooklyn Union Gas Company required Left and right couplings and nipples but would allow unions when the collar nut was doubled center punched.

Jake