Okay to use a threaded disconnect on pump?

[mshumack]

I'm replacing my 2HP Whisperflow Pool Pump. The piping is currently solvent welded at the intake and outlet so I have to cut the pvc pipes to remove the pump. Is there any problem using those threaded couplers ( the ones with the o-ring inside) at the inlet/oulet so if I ever have to remove the new pump I can do so easily.

Is there any downside (other than the cost of the fittings) to using these couplers?

[jongig]

I'm replacing my 2HP Whisperflow Pool Pump. The piping is currently solvent welded at the intake and outlet so I have to cut the pvc pipes to remove the pump. Is there any problem using those threaded couplers ( the ones with the o-ring inside) at the inlet/oulet so if I ever have to remove the new pump I can do so easily.

Is there any downside (other than the cost of the fittings) to using these couplers?

There is no downside so long as you don't change the inside diameter of the pipe. Some of the connections you mention are not "full port", meaning that they are not the same ID.

Technically speaking you are adding about 5 feet equivelant of straight sch-40 PVC when adding the coupler but that's not enough to worry about.

jongig

[CarlD]

As a firm advocate of PVC and "welding", I'm appalled that they didn't use threaded fittings for the pump. The only time I've seen that is the pump from a Jacuzzi bath tub. You can use threaded or even welded disconnects. They make them as just quick-connects, or combined with ball valves. I especially like those as I can shut off a line and THEN remove part of it.

[waste]

Hey there:)

What I think you're talking about is a 'union'. They are truly a godsend when you need to work on the attached equipment!

The only possible downside is an o-ring issue (i.e. lost, pinched or dryrotted) but those are easily prevented and, even if they happen, the o-rings are inexpensive:cool:

I'd throw one on and leave enough room for a coupling between it and the pump, just in case... ;)

[CarlD]

Comes closing time, and those o-rings come out. I lube them with silicon lube,and slide each into a zip-lock bag. Then I write on the bag, with a sharpie, which union or shut-off/union it came from. Then I throw all the zip locks into one big zip-lock so they are all together.

Coming soon...I"m just waiting til the water temp is down. I've got the cover on, all but one end, and my solar panels are blown out. Even the skimmer is shut and I'm using the low drain.....

[mshumack]

Thanks everyone. I used the Unions on both intake and pressure sides. However I now have a small leak/drip where the 2" threaded PVC pipe goes into the pump discharge port.

The Pentair instructions say do NOT use teflon tape, so I used only teflon pipe dope on the threads. When I removed the fittings from the old pump it looked like the installer used only a clear rubber-like "silicone sealer" (like used on a car's valve cover gasket) on the threads of the PVC pipe - no signs of teflon tape/dope.

What do you guys use?

Thankfully I installed the Unions (instead of gluing a coupler in) so I can easily remove this piece of pipe and reseal.

[waste]

That union is already coming in handy!

I've always used teflon tape on the threaded connections, but if Pentair says not to, so be it.

When a pump's discharge port gets to be a PITA to stop the drip, I'll use an o-ring to help seal the threads. You may be able to do this without having to fully unscrew the male adapter :cool: (but it's best to reapply the pipe dope).

Good luck with the fix!

[CarlD]

That union is already coming in handy!

I've always used teflon tape on the threaded connections, but if Pentair says not to, so be it.

Until the warranty expires!

[Ohm_Boy]

I only know of two reasons not to use tef tape... I mean, besides having the manufacturer say not to.

1) Back in the day, we were told to never use it on hydraulic systems, because of the risk of getting a shred of it into the spool valves, and wedging into them. They are a lapped fit, and it doesn't take much to foul them. You have to be REAL careful to always ensure that there is none off the threads, 'specially when there are lots of them to make up. I can't imaging a piece of it causing a real problem with a pool pump and filter, but I AM an idiot, so... you know.

2) Too many layers of tef can over-stress a fitting, and even cause a fracture.

Pipe dope is like Samuel Adams... always a good decision.