Bore hole pump question

[hummer]

Hi,

I have just had a 10hp bore hole pump re connected to the electricity supply and water is pumping just fine, one question I have is what would happen if the valve which connects the water from the pump to the irrigation system was closed and the pump was switched on, would there be a huge build up of pressure or something and blow something on the pump, or do pumps have some sort of pressure switch to stop this ?

Thanks

Scott

 

[Valveman]

The pump would build up 100-150 PSI and then would not be pumping any water. The pump/motor will last maybe 5 minutes at deadhead condition, then you will need a new pump. You can put a pressure relief valve on the line that will pop off enough water to keep the pump cool in a valve closed condition. A pressure relief valve works best when in combination with a Cycle Stop Valve and a pressure tank. The CSV turns any pump into a variable flow pump that will produce the exact amount of water you are using while maintaining a constant pressure on the system. This way the pup comes on automatically when you open a faucet, matches the amount being used, then shuts the pump off when you shut off the faucets. The pressure relief valve would only pop off if there was a failure and the pressure switch did not shut the pump off when needed.
Here is a link to a reference.
https://cpkits.com/collections/pump...s/csv3b2t-2-threaded-b-model-cycle-stop-valve

Here is a link to a graphic so you can see how it works.
http://www.cyclestopvalves.com/simple/irrigation.php?anim=1well

 

[Sponsor]

 

[LLigetfa]

Not sure why Cary did not mention his Cycle Sensor to monitor the amps to detect a deadhead condition. @valveman could it be due to the pump being 10HP?

 

[Valveman]

Not sure why Cary did not mention his Cycle Sensor to monitor the amps to detect a deadhead condition. @valveman could it be due to the pump being 10HP?

No we make Cycle Sensors for pumps up to 500HP. Yes the amps will drop when pumping against a deadhead and the Cycle Sensor would see that and shut the pump off. But I would rather use a pressure relief valve to protect against high pressure.

Done correctly and using a Cycle Stop Valve, pressure tank, and pressure switch for pump control, the pump would never be in any danger. The pump would automatically come on when you need water. The CSV would make it produce the right amount of water at a steady "constant" pressure, and the pump would shut off automatically when no one is using water. Then the Cycle Sensor would just be for dry well and rapid cycle protection, just in case the well was pumped dry or some component of the pump system failed.