UNIONS ON GAS PIPE (2023 Update)

[Tim]

I have never heard more different opinions on anything.

Can you use unions to connect gas pipe? Or rather, is it LEGAL to use unions to connect gas pipe?

Some say YEAH BUT HIDE THEM, some say NO WAY, some say SURE, I'VE DONE IT FOR YEARS. I was replacing some gas pipe and the guy at the plumbing wholesaler asked if I wanted to do the connection with a union or a right-left pipe and fitting (giving me a choice). I've always done it with a right-left (though I don't like that way) because I thought that was the code.

Any thoughts?

Thanks

[Bill]

There are unions at my meter.

[Wayne Whitney]

If I recall, the Uniform Plumbing Code only allows unions at appliances and at the meter. These have to remain exposed. Anywhere else you need to use a left-right coupling.

For a more definitive answer,

has a recent draft of the UPC available for download, and you can find the actual rules.

Yours, Wayne

[jamesgangnc]

That's the only place I have seen them used as well.

[dpb]

... There's rarely if ever a need to disassemble anywhere except at those locations as a routine/planned event, so little need afaics for anything other than standard fittings elsewhere.

I would have assumed the question wasn't for in a buried line, certainly... :)

--

[Steve Barker]

Unions are a necessity when using screw together pipe. Anyone who says that they are not allowed are just full of shit. Hell , look at your meter, you'll find at least two of them there.

[fftt]

Actually as unbelievable as it may seem unions, are not allowed (per current code) even in accessible locations, except at the meter. A left-right coupling is required.....which serves (more or less) the same function as a union but uses tapered thread.

That said, my 1930 (worked by professional plumbers up until 1979) gas supply has a few unions .....no problems so far. :)

cheers Bob

[Craig M]

Actually as unbelievable as it may seem unions, are not allowed (per current code) even in accessible locations, except at the meter. A left-right coupling is required.....which serves (more or less) the same function as a union but uses tapered thread.

That said, my 1930 (worked by professional plumbers up until 1979) gas supply has a few unions .....no problems so far. :)

cheers Bob

[Billbob]

They are allowed at the appliance but no where else like under a house where a leak can build up!

[CFH]

The section that says unions need to be after the appliance shut of valve it talking about appliances. If some one interprets that as unions are prohibited they would be incorrect. No where in the fuel gas code does it say unions are prohibited. The section that talks about piping 403.10 piping joint shall be suitable for the pressure and temperature. If a union is good after a gas valve it is good before. There are unions on meter bars and gas risers. There is a section that states what fittings can be used in concealed locations and unions are not included in the list

[MG]

You obviously aren't a licensed plumber. Unions are only approved outdoor, which is at your meter location(bushings are also illegal unless outside, and this is because the gas company will use whatever they want because they have authority), or on the downstream side of the gas valve of an appliance. And they only approve them there because a flexible connecter is basically a union, and some manufacturers recommend that you use a hard connection to the appliance, which would constitute a union. Read your code book brother before you put bad advice out to the public.