Replumbing pump, avoiding cavitation

[IceShadow]

Lubed up the o-rings, tightened all four unions involved. Didn’t open and lube the new Jandy valve. Not sure if that’s needed but I’m assuming it’s not.

Pump wasn’t priming before and I’m pretty sure it’s the seal plate as outlined in other threads, but I’ll give this a half hour or so to cure and fire the pump to see what happens.

 

[ajw22]

What do you mean by "street elbows"?

 

[generessler]

I remember reading somewhere that there should be a straight run of pipe into the pump (3 to 5 diameter pipe length) If you move your union either to the pump inlet or closer to the valve, it may work. Not sure where I read that.

Good call. It's mentioned that you should have a 10" straight section on the suction side in the Intelliflo manual. It's a 2" fitting, so 5x.

 

[1poolman1]

What do you mean by "street elbows"?

 

[IceShadow]

What do you mean by "street elbows"?

They have one side like a normal elbow and the other side like the pipe. Only way it would fit.

 

[ajw22]

They have one side like a normal elbow and the other side like the pipe. Only way it would fit.

I see what you needed.

Never heard that term before.

 

[IceShadow]

I see what you needed.

Never heard that term before.

It’s how it’s labeled at Home Depot

Anyway I thought I’d give the pump a shot to see if it would prime. No dice again. Air coming from a return but no prime. Probably leaking into the impeller via the damaged seal plate. Gonna have to wait for those parts.

 

[IceShadow]

At some point maybe I should address this but it’s been this way since we moved in and I’m not sure messing with it is a good idea.

 

[Flying Tivo]

It was annoying me too since the first picture you posted. I guess if its not broken, dont fix it. It will need some digging for sure.
Have you tried isolating one suction side while priming and then the other?

 

[IceShadow]

It was annoying me too since the first picture you posted. I guess if its not broken, dont fix it. It will need some digging for sure.
Have you tried isolating one suction side while priming and then the other?

Yes. No dice. Pretty sure it’s the seal plate being all chewed up.

 

[generessler]

Below is what the manual recommends.

You can use sweep 90s into the pump.

If possible, it is advisable to follow the manual for the straight run, but I would not worry about it if it was not easy to do.

Also, the pump should prime just fine at lower speeds like 2,400 rpm unless the pump is really high above the pool.

I would set the priming speed at about 2,400 rpm to about 2,750 rpm and that should work fine.

View attachment 419193

Fwiw, I'm intending to try these instead of standard in-line unions to help keep the suction side run smooth for my new VSP.

 

[IceShadow]

New seal plate is installed and pump is up and running.

Question - my old Jandy valve was able to turn 360°. I found this useful as I could turn it to the pump side and seal it off (with the pump off of course) before opening the lid to clean the pump basket. Then air wouldn’t get into my suction side pipes and it would prime quicker once the lid was back on. I think I read that there’s a plastic tab stop inside the valve you can break off to make this possible. Should I do that here? Or should I leave it so you can’t stop toward the pump?

 

[ajw22]

Look under the handle and you will see the stops. You can break them off if you want complete rotation.

It is up to you if you feel confident no one will turn the valve and dead head the pump.