Swollen massive PVC pipe out from pump, into sand filter

[jared77]

Can anyone tell me what may have done this? I have a salt water pool , I have a pool cleaner which runs through the day also.

I have a chlorinator, and sand pump. I came home to my power off at my house, to find this was the issue - check out the swollen pipe coming off my pump going into my sand filter.

Has anyone seen such a crazy thing? Its late here but I'm going to call the pool shop tomorrow.



I took piping off, no blockages I can see now. I took the top off the sand filter, and this seemed not to blocked although it had a little bit of fake grass in the filter but not crazy amount.

Im afraid to repair the pipework for it to occur again? I also hope the sandfilter handle held up to the pressure as I notice some water seeped through aroudn the handle

 

[JohnT]

Welcome to TFP!

Wow! Do you have a heater? That's about the only thing I can imagine causing such a thing. Maybe flow shut down into the pump causing it to overheat the water inside.

 

[Costas > DownUnder]

Wow, crazy....!

Is that schedule 40 rated PVC pipe?

Was the pump run at any stage with the filter handle set to an incorrect position which could have shut off the flow?

 

[JamesW]

Probably running with no flow.

Running with no flow creates hot water at the pump and high pressure.

To get the result, you pretty much had to have heat and pressure if it's schedule 40 pvc.

Do you have a picture of the whole system?

 

[woodyp]

You'd think a pump would burn up before reaching that point.

 

[JamesW]

I suspect that it's a valve configuration error on the return side.

For the pipe to expand like it did, I think that you need really hot water and pressure.

If all water flow is blocked at the return side, the pressure will be high and the water will get hot from being churned by the impeller.

There will also be some heating of the water from the motor heat being transferred to the water.

The motor does not have to work any harder. So, it makes no difference to the motor from a power standpoint.

The only extra heat that the motor will get is from the hot water.

Heat from the water will be transferred to the motor by conduction through the pump and some convection through the air if in an enclosed space.

The motor transfers some heat to the water during normal operation. Since the water continues to heat up, the transfer of heat slows down and eventually reverses as the water temperature exceeds the motor temperature.

So, the motor might have gotten too hot but maybe not.

 

[Jimrahbe]

James,

What do you think it did to the pump itself?? I have heard it can warp the pump housing and distort the threaded input and output ports...

Thanks,

Jim R.

 

[1Sammy]

If he has a heater isn't it after the pump and filter ? Because of the angle that piece of pipe looks to be a piece of flex but OP is calling it PVC, wow...

 

[JamesW]

I would check the pump basket. If it's ok, then the rest of the pump is probably ok. If it's deformed, the rest of the pump is more likely to have damage.

If the inlet and outlet are pvc, then they are probably going to leak. If they are hi-temp unions, they are more likely to be ok.

If the pump basket is deformed, I would open the pump and replace the seal and gaskets and check the impeller and other parts for damage.

I suspect that the valve configuration is incorrect and that should be figured out before running the pump again.

 

[Bama Rambler]

The pressure rating for PVC piping is at 73ºF and it gets derated as the temp goes up. The charts only go up to 140ºF and at that temp it gets derated to .2 of the initial pressure rating, so at boiling temp (~200ºF) the piping basically turns into a soft balloon.

Those pumps running with a blocked discharge will build heat pretty rapidly. I'd be surprised if at least the seal wasn't damaged. Maybe you'll get lucky and that's all that's damaged.