I 'inherited' a water setup whereby an old piston pump is being used to deliver well water from a drilled well. The pump seems belt driven, so I was told it is likely a piston pump. Lately, it has been getting rushes of air in the line (that cause it the pump to lose its prime) after almost 2 years of near-seemless operation. I pulled the pipe and it was actually 42 feet long, with a foot valve. Can this even work?? I thought these pumps were limited to 25 feet of down pipe. Any thoughts or input will be greatly appreciated

 

The amount of droppipe isn't what is important, it is the water level from the pump down. That needs to be 25 foot or less, hence only 30 foot of droppipe is needed.

bob...

 

Thanks for your quick reply Speedbump! I did not know that this is how the measuring worked.
The water level starts at 24 feet below the pump.
Should I be looking for piping cracks in this line then?

 

Yes, I would. Actually you can just change it out with new pipe, 30 feet with a new brass footvalve while your at it. That old pump will probably do a little better than 25 feet, since it will provide a little more vacuum than an impeller type pump will.

If you can get the pump lower (closer to that water level, it would work better too.

bob...

 

Thanks for the advice. I will do this on the weekend when I am home long enough that I can run to the hardware store in the even of a catastrophy when I put this all together again (speaking from experience). I'll let you know if it solved it.
One question: Why change the length of the pipe from 42 feet to 30 feet?

 

Mainly because that is all you need. Any more pipe just adds a little friction loss.

bob...

 

Might look at that old pipe there for pin holes from electrolysis. Most of the time it in the threads. this will let it lose the prime.

ED

 

Hi guys,
Thanks so much for your input.
I did in fact have leaks in that pipe!
I am still getting a little air in the system. I have one inch black plastic (PVC?) pipe. The first time I ran the pump after replacing the downpipe, I got a whole wack of air (after it was working almost properly and after it was properly primed repeatedly) , because the joint at the elbow was leaking. I could see/hear it. I made sure that nothing had gotten into the pipe where it connects to the elbow (Im working in clay, so it is a messy job) and re-tightened it using 2 clamps.

I suspect that this connection is still leaking a tiny bit even though soapy water shows nothing. Is there anything I should be spraying or spreading on the connection either inside or out to seal it better?

Compared to before, the system is running great, but since I have the hole still open, I thought I should just make sure.
Any thoughts?

 

I know about working in clay, especially when it's wet.

The best way to seal up that poly pipe is first be sure your putting it on a barbed fitting not a plain piece of pipe, then get the hair dryer or a torch and heat up the poly where it will slip over the barb fitting. Don't melt it or make it shiney, just heat it up so it's more pliable. Then slip it on the fitting and tighten both clamps as quickly as possible before it cools. That should do it.

bob...

 

Bob- It was raining as I was working yesterday, but it was the only day I had free to spend the time on this.

I do have the correct connector.
I think I heat them too long. It turns to a bit of glaze when I do it. I will be more careful in the future. Thanks again for all your help!

 

I had probably over-heated the pipes a bit when I originally connected them. I suspect a very minor leak although I can't tell even with the soapy water. Do you think it is worth it to heat it again and re-clamp it, or would that be a potential pandora's box?

 

That would be your call.

bob...