Impeller threads keep stripping

[hemicharger69]

Second Hayward impeller I bought. Threads keep stripping. Century B230SE 2HP filter pump. Hayward 4.1" impeller. Brass threads stripped flat. brass filings in the impeller screw cavity.

New pool motor works fine. Impeller just spins loosely on pump shaft. Doesn't tighen.

Has anyone tried putting in a steel sleeve and tapping threads?

Why new impeller threads strip ?

 

[proavia]

What motor, pump and impeller?
Some impellersrequire a setscrew to hold them in place after fully installing the impeller on the motor shaft.

 

[hemicharger69]

Motor: Century B230SE 2HP
Impeller: Hayward SP2615C Impeller
Pump: hayward super pump sp2600x pump series

 

[1poolman1]

Second Hayward impeller I bought. Threads keep stripping. Century B230SE 2HP filter pump. Hayward 4.1" impeller. Brass threads stripped flat. brass filings in the impeller screw cavity.

New pool motor works fine. Impeller just spins loosely on pump shaft. Doesn't tighen.

Has anyone tried putting in a steel sleeve and tapping threads?

Why new impeller threads strip ?

Unless it is a VSP, a 2hp pump is too much for virtually any residential pool. When the pump shuts down, listen to hear the motor being forced backwards as water runs out of the filter backwards. It is unscrewing the impeller. Next time the pump starts it will destroy the threads. Super Pumps never had a reverse thread screw to prevent this. Hayward didn't use them until their NorthStar and then the Tri Star. Next time, put a 1hp impeller on. It can go right on the motor with no issues and you likely won't notice a reduction in water quality and it may eliminate the problem A check valve between the pump and filter will help as well.

 

[hemicharger69]

That make sense. But I didn't see or hear the filter water force the impeller backwards. Maybe a little. I tightened new 3rd impeller on pump motor shaft so hopefully it doesn't loosen when the pump motor shuts off. Not sure why more horsepower causes the impeller to loosen when pump motor shuts off. Wouldn't water from the filter cause 1hp or 2 hp impeller to loosen just the same?

 

[1poolman1]

That make sense. But I didn't see or hear the filter water force the impeller backwards. Maybe a little. I tightened new 3rd impeller on pump motor shaft so hopefully it doesn't loosen when the pump motor shuts off. Not sure why more horsepower causes the impeller to loosen when pump motor shuts off. Wouldn't water from the filter cause 1hp or 2 hp impeller to loosen just the same?

Not sure the exact why, but this issue is seen more on larger (1.5-2hp) pumps most often. Could be that the impellers are physically larger and the water coming back from the filter has more surface to push against (like a larger sail catches more wind).
Used to only see reverse-thread screws on pumps starting at 1.5hp, now it is used on virtually all pump sizes.