Connectimg Unions into new pump

[cody21]

So reading about how to screw in union threads into a new Pentair pump seem to be all over the place. Looking for guidance. We don't want to have leaks and have to redo everything.

- Teflon Tape ?
- Pool / Spa Lube?
- Nothing. Just tighten, then max 1 more turn ?

Edit : Can we reuse the previous unions? Clean them good ? Or is that frowned upon?

TIA

 

[Jimrahbe]

Cody,

First they have to be actual pump unions, not the kind of stuff you can buy at Home Depot..

Pump unions have an O-Ring on the threaded side that seals the threaded end against the pump.

You should not need any tape or pipe dope..

You can see the extra O-ring on the threaded end in this pic..

Thanks,

Jim R.

 

[cody21]

Thanks Jim. The In flow union looks like that. I was thinking of replacing it with same, since it's old. (If Leslie's has it). The Out to the Filter looks nothing like a Union, just a threaded 2" Pvc of some sort. THAT one was mostly my concern. We were hoping to be able to just clean it really well and reuse it. Otherwise to get one of those unions in your pic, we're needing to re-engineer the section for the Out.

 

[1poolman1]

Thanks Jim. The In flow union looks like that. I was thinking of replacing it with same, since it's old. (If Leslie's has it). The Out to the Filter looks nothing like a Union, just a threaded 2" Pvc of some sort. THAT one was mostly my concern. We were hoping to be able to just clean it really well and reuse it. Otherwise to get one of those unions in your pic, we're needing to re-engineer the section for the Out.

While it is not likely to be needed if the union is tightened properly against the O ring, I have always used 3 or 4 wraps of Teflon tape on those threads as I don't like being called back for a tiny drip. Was more than worth it to me for piece of mind (what I have left, anyway). Cheap insurance.

 

[Jimrahbe]

Cody,

I don't think it hurts to add some tape, but if you add too much, then the threaded end will stop turning before the O-Ring is seated all the way.. Common sense applies..

Thanks,

Jim R.

 

[1poolman1]

Cody,

I don't think it hurts to add some tape, but if you add too much, then the threaded end will stop turning before the O-Ring is seated all the way.. Common sense applies..

Thanks,

Jim R.

Threads on those unions aren't tapered like a MIP. They are straight and will go all the way in until the O ring hits and then a little more to seal. Three of four wraps has never interfered yet. I can feel when something is on the verge of damage, learned the hard way at times. Since most of my work for the last 15-20 years has been at least 25-30 miles from home, I just didn't want to take the chance. YMMV. But yes, common sense says more is not actually better.

 

[cody21]

While it is not likely to be needed if the union is tightened properly against the O ring, I have always used 3 or 4 wraps of Teflon tape on those threads as I don't like being called back for a tiny drip. Was more than worth it to me for piece of mind (what I have left, anyway). Cheap insurance.

Stupid question. Do you use the full width of the tape to wrap 3-4 times, or do you just use small narrow strips that go into the threads? I've seen it both ways and some of the pros only force into the threads. I hope that makes sense. We've done this on other Pvc projects (full width) and found it hard to tighten, and then a leak.

 

[Jimrahbe]

Threads on those unions aren't tapered like a MIP.

@1poolman1

I did not know that!!!

I have never used the tape, and have never had a leak, but then I've only installed a handful of pumps compared to you.

Knowing that the threads are not tapered, then I agree it sounds like a little tape is not going to cause any issues and just might save the day..

Thanks for the course correction...

Jim R.

 

[cody21]

Threads on those unions aren't tapered like a MIP. They are straight and will go all the way in until the O ring hits and then a little more to seal. Three of four wraps has never interfered yet. I can feel when something is on the verge of damage, learned the hard way at times. Since most of my work for the last 15-20 years has been at least 25-30 miles from home, I just didn't want to take the chance. YMMV. But yes, common sense says more is not actually better.

Thanks you so much ... Sounds like a couple turns of teflon will seal the deal, so to speak. I just hate it when we finish such a complex job only to discover dripping leaks and have to UN DO everything and start over. So frustrating.