Another gas pressure test question

[Roberto]

Greetings all:

This is about how to cap the location of the new-to-old junction of a new gas line for the pressure test, in a way that will allow final connection after the pressure test. I looked but didn't find the answer to this question in old threads.

I'm adding new natural gas plumbing to a small gas fireplace. The line will run from an existing, capped-off 1/2 inch stub in the attic (I'm not sure what the stubbed-off piece was for, but it's there, and it's not a drip leg or the like), to the shutoff valve by the appliance. The work is permitted, and straightforward, but there's one detail that I haven't finalized about the pressure test.

There's no way that I'm going to pressure test the whole house of decades-old gas plumbing, and local procedures explicitly allow me to pressure test only the new plumbing, and leak-test the connection to the old, after final connection, with a bubble test.

So I'm planning to put the pressure test at the appliance end of things (no valve, just pressure test assembly) and cap the other end of the new plumbing, in the attic. It's NOT going to be concealed, so I think I'm OK leaving the new line capped a few inches from the existing old cap, then planning to make the final, post-pressure test connection with a right-and-left coupling and ******. I'm confident that this is code-compliant and logical, but I'm wondering if there's some other, standard way that plumbers do it that will give the local plumbing inspector that cozy feeling that things have been done the standard way.


This is in California. A union is definitely not allowed, of course.

Thanks for any advice that you can offer.

 

[motorcycle79]

sooner or later u need a union.. cant believe u cant use a union but it is california

 

[littletoes]

It depends upon which code your local authority is using.

Recently, this part of Washington just adopted a new code a couple of years ago, that does NOT allow the use of unions, OR left-right ****** and couplings in concealed locations.

The only thing that would be allowed would be a re-test of the entire system, after the addition was made.

This was always the code anyway, depending upon the amount of piping that was to be installed, in comparison with existing.

A very good question would be, if you are so concerned with your existing piping being able to hold a test....Then SHOULDN'T you be concerned with just leaving it "as - is?".


Another question of mine would be (and I am still unsure of the amount of piping you are talking about adding..), how many more btu's are you expecting your main to carry? And has it been sized according, and found sufficient?

 

[mrobins297aaa]

I don't know **** about the codes in ca, but I assume you have a gas meter. why not just hook it all up, make sure all the appliances are off and pencil mark the most sensative dial on your meter and watch to see if it moves. if the pointer doesn't move from the pencil mark your good to go........very very simple, its the way the gas company tests around here. When we did new homes we would get the entire home gas piped and the gas company would come out, install the meter and put a pencil mark on the face of the meter and watch to see if the needle would move ,thats all they did, we never soap bubbled any joints or pressure tested any of it.
check and see if the inspector will accept that.

As far as pressure testing goes when you subject the system to higher than normal operating pressure you can create leaks that would never occur.

we only pressure tested gas piping that was concealed in wall spaces.

 

[W-Cummins]

Why not connect it to the old work with a valve? That way you can just test the new work, then open the valve and bubble test the other side of it.

William....

 

[mrobins297aaa]

Why not connect it to the old work with a valve? That way you can just test the new work, then open the valve and bubble test the other side of it.

William....

best answer

 

[gmwelder86]

Why not connect it to the old work with a valve? That way you can just test the new work, then open the valve and bubble test the other side of it.

William....

best answer

Do this all the time, you can either leave the valve in, I would take the handle off, this is also done all the time. Or test to the valve pass your inspection and replace the valve with a left right ****** or union depending on what you want. And a union in a attic I put them in all the time when connecting to equipement, it is nonsense to completly hardpipe to a funace without a union but I have seen it done.

 

[Roberto]

Thanks for all the good responses. I have a few thoughts:

Unions: Not allowed. Here are snippets from various codes, California and local:

"Unions (inline couplings) are only permitted downstream (after) appliance shut-off valves, meter locations, and immediately downstream on building shut-off valves. The use of right/left couplings and ******* are required in all other locations. Unions shall not be installed in a concealed location. (CPC 1211.3.2)"
and

"In all other situations where a union-type connection is required (except at meter and at appliances), a left-right ****** and coupling must be used."

Right-left coupling and ******: It's in a lousy attic: not concealed, so it's OK.

Pressure-testing the whole house: I'm not doing anything to hurt the existing plumbing, and I have no safety concerns about the existing plumbing, so I'm going to do what the codes require, which is to check the new plumbing. If someone else wants to conduct unpaid and unauthorized 15 psi tests of old plumbing systems in old houses, that's OK, but it's not my crusade.

Sizing/capacity: Thanks for the reminder. Doublechecked, and OK with some headroom.

Connecting with a valve: It's an idea. I'd prefer to test it overnight. But the house is occupied with a family with kids, and they can't do without heating and hot water, so one side of the valve would be new new plumbing under pressure, and the other, working plumbing with gas. It goes against my instincts to do that. Any code issues with this idea? The inspector will be totally by-the-book in this case.

 

[Norcal]

I doubt a inspector will allow a test of only the new piping, the entire piping system will have to be tested,BTW a left/right coupling/****** is a PITA but they work.

 

[Roberto]

Thanks for your replies. I went down to city hall and talked to the inspector. He's OK testing just the new piping, and said, "as long as it's not concealed, just put in a regular gas valve and test against that." So I'll do it that way, but spend the money on a better valve, so if I'm losing pressure during my tests, I'm not questioning whether it's the valve. $15 valve instead of $5. I'm not going to make any money on the plumbing part of this job, for sure. I based my quote on a giant brain fart: easily accessible gas, unused tee, right next to the chimney chase. As I drove away from the house, freshly-sgned contract in hand, I realized that the line was for the other unit in the house. So now I'm crawling around in the attic, wondering about that huge wasp nest in the corner.

I'll make a little money on the rest of the job.

Anyway, thanks again for the advice.

 

[littletoes]

Aw heck! Didn't realize it was a bid job...I was thinking it was for your own house/shop combo.

Since we're talking a money job, and you don't want to shut the system down any longer than needed, yea I'd ad the valve, and run the pipe.

Home-owners almost never want to take the most expensive route!

For future reference, don't be afraid of left-right ****** and couplings, they are actually quite easy to put in. Never had any problem with them, they are just not legal here any more....code change, and the new code is ****.

International Fuel Gas Code-*****, and I hope the engineers that wrote it read this. That Text is FULL of holes, and extremely CONTRARY to ASME Mechanical Code.

Perhaps in time, with needed information added it will become something...but for now, its all Inspector Interpretation.