"Smarty" wrote in message
...
Wayne,

I wonder if unions are not allowed because they have some greater risk of
failure?????

Smarty



"Wayne Whitney" wrote in message
...
On 2006-11-09, Smarty wrote:

I thought about putting unions all over the place so that each
segment could be independently tightened. I have not seen
professionals use this approach, so I am guessing this is not a
great solution.....

In my building code, unions are only allowed "adjacent to accessible
equipment". That is, if you hard pipe an appliance, you can use a
union for the final connection. Otherwise, unions are out. You can
use a left/right coupling, though.

Cheers, Wayne



Unions are much more likely to leak than other fittings. That is why codes
and inspectors require minimizing them. The key is to have good clean
threads, sealed with tape, dope, or both. Your inspector likely has a
preference for sealers. Many novices do not adequately tighten the joints.
If you are considering re-tightening one, then you probably did not tighten
it enough the first time. Tighten them really tight and never back one up.
Especially if you have several joints in line, you can always go whatever
additional part of a turn is needed for alignment. Unless you have a really
long wrench you generally cannot break the pipe or fitting by tightening it.
If you do break it, it is usually easy to replace at that time. Try it on a
few fittings to see just how much they can be tightened before breaking. If
you are unsure of your skills, you can seal off and test sections of pipe as
you go.

Don Young