Copper Unions - do they work?

[CountryBumkin]

I bought two 1 inch copper fittings to install on either side of my whole-house water filter canister. The idea was to make installation easier.

I can't get them to Not leak. No matter how tight I make the Union Nut, it just won't stop dripping.

I've taken them apart several times, everything is aligned and clean. They just continue to leak.

Are these Unions a bad idea? Is there some installation or assembly trick? If just one leaked I would naturally blame myself - but since both leak, it makes me think it is the design/part rather than my assembly method.

I'm ready to cut them out and just solder in some straight pipe. Need to get this fixed this weekend.

 

[Cacher_Chick]

The sealing face can be damaged by overtightening, and some come with a sealing washer that fits between the faces. If they are imported, there could be additional defects.

 

[Sponsor]

 

[hj]

Put pipe joint compound (dope) on both surfaces and the large union thread then tighten them.

 

[Flapper]

I was wondering about copper unions too; I once got copper unions for 1" pipe and the mating surfaces were just metal-to-metal, no rubber stuff. I didn't use them because they didn't fit, and that was probably a good idea because if I used them, they'd probably (also) leak. I found that these unions have bad reviews on Home Depot and Lowe's; people say they always leak. Is pipe dope the correct way of using these unions?

 

[Cool Blue Harley]

Love copper unions. I think installing them on your water filter was a good idea. They will not corrode even after years of use. Metal to metal is fine, torqued just right. If you do have a problem, a light coating of pipe dope is the ticket, as mentioned above. I've only used American, NIBCO or equivalent. Don't know about Lowe's or HD. Do not shy away from copper unions.

 

[CountryBumkin]

Thanks the for help. I didn't know about using Pipe Dope.

 

[Jadnashua]

If you overtighten them, they may not leak, but when you try to reuse them, there may be a ridge on the mating surface, and unless you get them aligned exactly the same way, they may not seal the second time without a lot of effort.

 

[Flapper]

Love copper unions. I think installing them on your water filter was a good idea. They will not corrode even after years of use. Metal to metal is fine, torqued just right. If you do have a problem, a light coating of pipe dope is the ticket, as mentioned above. I've only used American, NIBCO or equivalent. Don't know about Lowe's or HD. Do not shy away from copper unions.

I think the ones they sell in HD is from Mueller.

 

[Kreemoweet]

Trying to use unions (of ANY type) on existing runs of pipe is a tricky thing, because those runs are rarely, if ever, perfectly aligned and
of the perfect length not to put undue stress on the union fitting. I always aim to build at least one of the connected runs AFTER the
union has been tightened.

 

[Flapper]

Trying to use unions (of ANY type) on existing runs of pipe is a tricky thing, because those runs are rarely, if ever, perfectly aligned and
of the perfect length not to put undue stress on the union fitting. I always aim to build at least one of the connected runs AFTER the
union has been tightened.

Does that mean unions should not hold weight?

 

[CountryBumkin]

I bought my supplies here http://www.supplyhouse.com/Copper-Fittings-130000 My local HD doesn't carry 1" copper fittings.
The brand is Elkhart.
I ended up cutting out the unions and soldering in pipe. I didn't see the reply about using Pipe Dope, and I needed to get this job finished on Sunday. I'll save those Unions for another project.

 

[Kreemoweet]

Does that mean unions should not hold weight?

Not sure what you mean. All types of piping are required to be supported by external means (straps, hangers, etc.) per the
plumbing codes and good practice. No rigid-type pipe or fitting should be strained or bent.

 

[Flapper]

Not sure what you mean. All types of piping are required to be supported by external means (straps, hangers, etc.) per the
plumbing codes and good practice. No rigid-type pipe or fitting should be strained or bent.

I mean an exposed loop, like for a valve, sticking out of a wall. Can unions be used on both sides of the exposed loop? The unions would have to hold the weight of the loop.