"Robert11" wrote in message
...
Hello:

Have done a fair amount of home plumbing type of work, but, surprisingly,
have never had need to use a "union".

Have to run a line from a washing machine water outlet to the machine, and
for various reasons, before I get to the hose itself, I could use a Union
in the rigid section to provide some angularity adjustment, as well as the
removable advantage they provide.

Have looked at them at HD, and frankly they make me very nervous.

What's your experience with these things.
e.g.,

Once you snug them up, do they tend to stay that way ?

Reason i'm asking is that there is no elasticity in the union coupling
itself, so it seems to me that if the threads back off, even a very small
amount, there will be leakage thru the ground and polished seat where the
two pieces actually come together.

Any thoughts on this ?
Safe to use ? Proven in practice pretty well ?

Are there any other types, or brands, besides the HD ones that are perhaps
of better quality ?

Thanks,
Bob
Unions are fine If you are going from Iron to copper you need a dielectric
union. Also when installing one coat the threads with pipe dope if a non
dielectric also coat the face, don't be afraid to tighten them. A union
should always be accessible. What I like better is a Left/Right nipple witch
also are made for dielectric use. Now if you want some flexibility buy a
flex hose. Basically pipe threads on the end of a stainless hose, They also
make a copper sweat flex. If this is going to be something you see
disconnecting now and then start off with a ball valve.