Pentair Pump Union replacement

[1poolman1]

Yeah, Pentair has its own weird (wider-spaced) threading. Hayward may have its own, too. All the standard and generic companies seem to have the same threading, however, oddly enough (maybe it's the same as Hayward?).

But I am dealing with old Pentair unions - I went to put in my new non-Pentair pump and, lo-and-behold, the unions won't screw onto it. I looked like heck for an adapter to screw onto the pump (I found a discontinued one that is the opposite of my situation - ie, if someone had a new Pentair pump and the existing unions didn't fit.).

I'm looking at split-nut unions, though it's hard to tell if they're quite right. I also have the union slip plumbed directly into my 3-way valve so, like you, I'm leery to go a-heat gunning. It's exasperating to be stymied by a lousy union.

Which new pump? Which old Pentair pump? All pump manufacturers use proprietary threads on the pump, they are not interchangeable.

 

[Brett M]

Pentair uses a “proprietary” thread pitch because, I was told, field techs don’t like to have to turn the union so many times. It’s honestly silly but that’s how Pentair rolls and then they get to charge you 10X the price of a standard union for their special union.

I guess carpal tunnel syndrome is an occupational hazard for pool plumbing

Yes. And this is causing me enormous exasperation as I go to replace my dead Pentair pump with a new non-Pentair one. Is there a good nut (the split kind, where the two halves screw together?) that will fit for the new pump, and keep me from having to re-plumb everything?

 

[Texas Splash]

Welcome to TFP! Might help to see some pics of what you are trying to do. Give us some details on the new pump and existing filter. Maybe we can give you some ideas.

Also see ----> Pool Care Basics