shallow well pump max press. 40psi

[Desertsun]

Hi,

I hooked up a new pump [craftsman 3/4 hp] to a shallow well , depth about 12 feet and got everything running great. I'm also using a 30 gallon Craftsman captive air tank, about 3 years old. This well is only being used for outdoor applications.

Pressure was about 60psi, lots of water, but I did notice the prime would drop off after 5-10 minutes of shut down, so I thought there must be a leak on the suction side, ruled out check valve because it's brand new and comes with the pump [plastic though], but never checked it out,

So after about 5 months of good use, the pressure drops off, slowly to 55, 50, 45 ....... now 40 where it stays solid, sometimes it will go up to 45.

Captive air tank fills good, but I had to adjust it's air pressure since it and the system were at 40,

I've checked suction side for leaks but can't find any, pressure side is rock solid. Is there a better test than soap bubbles?

I'm reluctant to open pump to check impeller & jets because in 15 years I"ve never had to clean a pump on this well & this pump has only been in service for 5 months, though it's a possibility,

==

a) loses prime when pump is off, did this from first day I hooked it up

b) max pressure is 40psi

c) no leaks on suction that I can see but who knows

Is there a foolproof way to test the suction side without dismantling everything,

Thanks for your help and suggestions,

Jeff

 

[vaplumber]

Replace the check valve and see what happens. It may be new, but it could still be defective. Also are you using a foot valve in the well? If so, install a new foot valve, and get rid of the check valve at the pump all together. The proper place for a check valve is at the bottom of the intake pipe in the water. The craftsman pumps are ok for mild to moderate use, but avoid the plastic check valves from sears. Hope this helps.

 

[Sponsor]

 

[Speedbump]

I agree with VAPlumber on the plastic check valve and footvalve issue.

If the pump doesn't come on at all but loses it's prime, the check valve has to be holding. Air leaks are next to impossible to find, but that's what you have. While the check valve is holding, the air leak is letting the water in the pipe in front of the check valve slowly run back to the static water level. Next time the pump comes, the valve opens and all there is for the pump is air, not water. Since pumps don't pump air and there is nowhere for the air to go, the pump has to be reprimed.

Just so you know, I'm not fond of Sears pumps either.

bob...

 

[Desertsun]

Thanks for those tips;

The way you have described it I can rule out the check valve, the pump does not come on when the prime is lost, plus I didn't do quite as good a job on the suction side as on the pressure side piping, so I have to redo that section.

The check valve screws into the pump and then the incoming suction pipe screws into that, and I had to use teflon tape because Craftsman says not to use anything but tape on the pump connections. . . so that's a weak link.

The last pump I had was a Myers cast iron 3/4 hp, it never clogged, but the outer casing cracked in a freeze. Is a Craftsman jet pump more likely to clog?

I have run some really rusty water in these gaseous bursts but no pump has clogged,

Is there a way to make a reusable pipe connection at the pump that you can dismantle in case you have to clean the impellers so you don't have to keep cutting the pipe, etc . ?

thanks,
Jeff

 

[Speedbump]

There is a fitting called a union that will allow you to easily disassemble the piping, but again I recommend the fewest amount of fittings in the suction line possible.

If your well is large enough to put a droppipe of no smaller than 1" 30' long with a footvalve on the bottom, your problem will go away completely.

bob...

 

[Desertsun]

Hi,

On the suction side of the pump at the bottom of the diffuser is a 'drain cock' that is leaking slowly, one drop every 20 seconds or so, the screw is as tight as possible, since this is plastic I don't want to force it,

Also, on the main suction intake of the pump, the nozzle part, underneath and on the nozzle, is a bolt screwing in to it,

What's it for? I can turn it easily either direction. Can it break the vacum?

thanks,

 

[Speedbump]

I don't think you have your terms correct, the venturi and diffuser are both in side the pump. The drain at the bottom is probably just that, a drain and is not on the suction. If it were on the suction, it would stop leaking water and suck air when the pump was running.

The screw may be the rinky dink backpressure control they put on their convertible jet pumps. They don't work and aren't needed for a shallow well application anyway. Leave it all the way out.

bob...