Threaded or Slip Unions?

[Magee324]

I'm plumbing my tank and I'm trying to figure out Unions. I'm going to glue PVC to the slip bulkheads on the underside of my Eshopps Eclipse L overflow tank. That part scares me a bit because it's permanently connected to the expensive overflow box. Any alternatives?

The main question I have is what kind of unions should I use? Should I use slip x slip or thread x thread or slip x thread?

I was thinking (thread x thread) so I can easily remove them and fix whatever mistakes I'm sure I'll make since this is my first build. Thanks!

 

[vanpire]

I would use the threads. A little more expensive and takes more time but you will appreciate when you have to remove it for any reasons. Use Teflon and you will be good. Leaks won't be an issue.

 

[Idoc]

I prefer slip... if you have to replace, it only costs you to replace the "other half" of the union with a new one... they're cheap! Plus, threads are a bigger chance for leaks than slip cemented joints. But, it will come down to preference and either will work just fine for you.

 

[mfinn]

I prefer slip/slip. IMO less chance for leaks.
But if you decide to go with threads, use a thread paste that's made to use with pvc. Teflon tape is not.