Goulds pump losing prime

[mrogge]

Hi. I've got a brand new goulds 1.5 drawing from a lake. Everything is new except for the pipe between the pump and the lake. There's a spring loaded check valve in the lake near the strainer. I also pressure tested the auction line and it seemed to hold at least for the short term. Heading back in a few hours to see if it held overnight.

I can prime the system by throttling the spigot after the pump. After priming the pump and all zones work great. But by the next day the prime is already gone.

I suspect a bad check valve..... though since it was holding the back pressure I'm not sure anymore. ***unless the check valve is faulty whereas the back pressure isn't enough to make a proper seal??

 

[Valveman]

A foot valve or check valve can only cause a loss of prime when the pump is off. If the pump is running all day and not shutting off as it should, the loss of prime is most likely a suction leak or a high spot in the suction line. But if it runs all day and loses prime overnight, it is most likely the foot valve. Plastic check/foot valves suck, because they don't check. Lol!

 

[Sponsor]

 

[mrogge]

I isolated and pressurized the auction line to 50psi. After 16 hours it was still at 30psi. There's no high spot on the line. It's a slope of about 8ft over 100.

 

[Fitter30]

Could be the shaft seal.