Explain unions please

[Wobblerlorri]

I know I'll need them, but I don't understand why. I'm going to plumb my new pump and filter this fall using 1.5 inch flexible pvc. I know I need gate valves on each pipe (outlet, inlet, and skimmer), but I have these questions:

1. What is a union?
2. What does it do?
3. How many will I need?
4. What's the best brand?

Thanks in advance!

 

[Chad1979]

Unions are screw on pipe couplers that allow you to disconnect pipe sections (without having to cut the pipe and replace it) from say your pump or filter or swcg if you have a need to repair or replace those items as well as for winterizing. I cant say how many you will need or what good ones are though. Someone else will need to give you those answer.

 

[Wobblerlorri]

Bump -- anyone done hard plumbing can help me understand unions?

 

[zea3]

I put a ball valve union on my intake line between the skimmer and the pump and the filter and return. I had a union (no valve) between my pump and filter also. When I needed to service the pump, I could shut off the valve and open the unions to remove the pump, replace the shaft seal and put the pump back without having to cut pipes and glue things back together. The union has an o-ring inside that helps it seal tightly. The two halves of the union screw together easily.

 

[zea3]

The "wheel like thing" on the line going to the filter is a union.

 

[zea3]

This is a ball valve union with the handle on it. Ignore the plain union at the end of the run. Not sure what I was thinking there!

 

[JJ_Tex]

Just think of unions as making things easier to replace (heater, pump, SWCG, etc.). You can simply unscrew them instead of needing to cut the PVC.

Here is a pic of mine, you can see the black ones before/after the SWCG, and white ones for the heater. I wish I had them also on the pump, but I do not.

 

[PoolGate]

There is no "need" for unions. They are a "nice to have" for servicing your plumbing. A lot of people remove the saltwater generator cell when they winterize the pool. Using unions, you could simple remove it and replace it with a straight piece of pipe. Multiport Valves fail and need service. Without unions, it would require cutting pipes to remove the valves. It is up to you the level of serviceability you want to add.

 

[newdude]

Hey miss !! So as you know, typical above ground plumbing leaves a lot to be desired. It’s all easy access but clamped together and ultimately comes loose and fails. Once you upgrade to PVC, it’s glued together permanently so you can’t remove the filter/MPV, pump, etc. Unions will secure the pieces together while making them easily un-do-able so you can service, replace or winterize/store any/all of the equipment pad.

I don’t care if you are replimbing a furnace, a bathtub or pool equipment, if you are already doing it, it makes every sense to set up all future repairs when it’s easy. The small increase in project costs will save you far more than they cost in grief when the time comes.

 

[Oly]

Unions also have an o-ring that provides the water seal at the connection. My Pentair pump came with two unions as did my CircuPool SWG. My cell will require maintenance and must be removed periodically and if my pump ever needs service or fails the replacement is a simple drop in.

 

[Wobblerlorri]

Thanks everybody! So for my setup, I'm guessing I should have a union at each outlet from the pump to the pool, and a union on the pump to filter run? I have gate valves for the pool outlet and inlets -- do I need a union after the gate valve too? I'm going to use flex pc.

 

[Flying Tivo]

I put 3 unions on the filter and 2 on the pump. The SWG has its own special size.

 

[otter86753]

Unions on the multiport of a sand filter are handy to deep clean the filter once a year.