tiny bubbles from closed loop ( help)

[daveyakiwchuk]

I plumbed in a Velocity T4 with a 1inch 90 elbow into the tank with about 100 1/4 inch holes for the intake . the returns are via 2 3/4 inch returns. Somehow I am getting tiny little bubbles constantley blowing into the tank. Ive gone over the intake and I am 100% there is no air leak on the intake, however becasue the pump is so quiet I can still hear the air entering the pump and being ground up? I have heard of cavitation but I do not believe this is the case?

Any suggestions?

 

[PeeJ]

is the the impeller housing sealed up real good?

 

[daveyakiwchuk]

the 1inch flex tube is right up tight and I have a hose clamp almost as tight as my ratchet can go.

 

[PeeJ]

well i meant the actual housing...like the assembly on the motor. is it all put together tight? perhaps it is a factory defect

 

[daveyakiwchuk]

looks bullett proof?

 

[Anonymous]

Do you have a ball valve between you tank and intake? Any true unions?

 

[daveyakiwchuk]

No, Just 1 inch ID flex tubing from my pump up to the PVC elbow I made. All joints on the elbow are sealed.

 

[daveyakiwchuk]

Here is the intake I made, It feeds down to the Pump via 1inch and clamps right on the pump with flex hose ( no barbs on pump)

 

[Anonymous]

Hmm. I wonder if its not just air that gets trapped due to turbulance in those 90's? How long has this been going on? If you shake the plumbing a little, do more bubbles come out?

 

[daveyakiwchuk]

Shaking made no difference.

 

[adminrxb]

Go bigger intake pipe size. A 1 1/2 or 2 from the closed loop drain to the pump intake and then reduce the intake pipe to 1" again where you connect it to the pump intake threads. This should help reduce some bubbles. Seems like that the pump can not pull water fast enough and starts chopping water that creates the tiny bubbles for you. Increasing pipe intake size will allow more water surface area for the pump impeller and provide enough water for it. Hope this helps.