Will Cavitation Damge my Pump?

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Noggin
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Will Cavitation Damge my Pump?

Postby Noggin » Sun 21 Feb, 2010 18:59

Warning: I'm a pool noob, so some idiocy may follow...

I spent a good part of the day replacing my booster pump. It was making a painfully loud squeal as it ran, so I assume it was the bearings. Local pool service company said that you can't rebuild the motor/pump I have (probably BS) but offered to install a new one for $550. So I said fuggit and replaced it myself.

After replacing the booster pump, I spent a few hours trying to figure out why my polaris creepy didn't work worth a damn. Wheels turned at about 8 RPM and I think should be 30 RPM and the tail didn't move. After a while, I finally figured out the quick disconnect and discovered that the filter there was slap full of silt and sand. Cleaned it out and now my creepy is super happy and my dog loves chasing it around the edge of the pool.

Once I got done working on all of that, I decided that my main pump is cavitating. It sounds like it chewing on rocks and I'm getting tiny air bubbles from the outlet in the pool. Am I going to hurt anything waiting until next weekend to try to work on it? I've posted a sound clip here . I'm almost out of daylight.


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Pool Clown
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Will Cavitation Damge my Pump?

Postby Pool Clown » Wed 24 Feb, 2010 08:45

Do you have an attached spa? Try putting the valves to spa (like you were going to use it) and see if that changes the cav.
Factory warranty service for Pentair, Jandy, Raypak, Polaris, and Paramount pool cleaning systems.
Noggin
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Will Cavitation Damge my Pump?

Postby Noggin » Wed 24 Feb, 2010 21:09

no spa
Noggin
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Will Cavitation Damge my Pump?

Postby Noggin » Sun 28 Feb, 2010 14:20

Still don't know if cavitation will damage a pump, but luckily the problem was easily remedied. The filter basket in the pump was largely clogged even though I couldn't see anything through the viewing bubble. Cleaned it out and the pump is quiet and I have pressure again.
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Pool Clown
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My Pool: Uses a Chlorine generator, not a Salt Water Generator (SWG).
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Will Cavitation Damge my Pump?

Postby Pool Clown » Sun 28 Feb, 2010 22:28

Oops, missed that one! Great news.
Factory warranty service for Pentair, Jandy, Raypak, Polaris, and Paramount pool cleaning systems.
starkraven

Will Cavitation Damge my Pump?

Postby starkraven » Sat 08 Jun, 2013 14:51

I've been told that cavitation is normal when your pump wants more water than your inlets supply. It occurs when I'm vacuuming. The pump basket never quite fills although I've got good suction in vacuuming. Once I'm through vacuuming and circulation returns to normal, the sight basket fills and everything's fine. I don't know if extended cavitation will harm the pump. i hope not.
Denniswiseman
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Will Cavitation Damge my Pump?

Postby Denniswiseman » Sun 09 Jun, 2013 04:32

When you are vacuuming you put an extra load on the suction and if your pump basket has air in it, it's sucking in air. It could be the pump basket lid "O" ring or even your hose. Try using silicon grease on the "O" ring first
I have experienced the filter working OK untill the suction is connected and then the pump basket drains out completely. Replacing and greasing the "O" ring cured it

However if you can vacuum OK you probably won't bother yet but bear in mind as a remedy for future problems
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mas985
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Will Cavitation Damge my Pump?

Postby mas985 » Sun 09 Jun, 2013 14:51

Cavitation will slowly destroy an impeller with pitting but it takes a while. But don't mistake air in the pump basket for cavitation because they are two different things although they sometimes occur together.
Mark
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18'x36' 20k gallon plaster/gunite pool, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge Filter, Solar Panels, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater
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Pool Clown
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Will Cavitation Damge my Pump?

Postby Pool Clown » Mon 17 Jun, 2013 10:21

This particular cavitation is occurring because you are:
1) extending the length of the suction line (the length of the vac hose).
2) that extra length is also a smaller diameter. Even though it is a 1 1/2, it is a vacuum hose which is actually smaller diameter than 1 1/2".
Factory warranty service for Pentair, Jandy, Raypak, Polaris, and Paramount pool cleaning systems.

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