Low Pressure Shallow Irrigation Well

[Cednite1]

Hello

I re-plumbed the piping on a shallow well. New check valve and new intake and output plumbing.

When the pump starts the pressure is adequate. However 2 minutes into watering the pressure drops. There is a bleed screw on the actual pump and if I slightly unscrew it water squirts out and the pressure increase and move back to the original pressure. If I tightened the bleed screen pressure decrease again.

Are there any suggestions what could be the issue.

 

[Valveman]

Sounds like you may have a suction leak.

 

[Cednite1]

Okay, I can get behind that idea. Can you add color on why you think that. I’m not challenging you just looking for education.

 

[Valveman]

When the pump is at low flow it sucks in air easily. When you open the plug and let more water out you are increasing the flow rate and the little air leak doesn't add up to enough to cause a problem. At low flow the little bit of air coming in takes over and you loose prime.

 

[Cednite1]

Perfect, thank you. I’ll re-thread the intake. I only used Teflon tape no dope. I’ll try both this time and see if that’s a fix.

 

[Valveman]

The leak is usually where plastic pipe screws into the pump. The pump gets warm and makes the plastic threads leak. I like a metal nipple for 6" or so on the suction side before going to plastic.