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Water Hammer - Shallow Well Suction Line
I have a shallow well pump in my basement that was previously connected to the well with about 80 feet of 1" plastic pipe. I recently replaced about 30' of this plastic pipe in the basement with 1" rigid copper to get it up off the floor. I now have a very loud and sharp water hammer when the pump shuts off. Previously the plastic would have a slap in it when the pump shut off. I only have a foot valve at the bottom of the well. I am considering putting in a Hydra-Rester in the suction line between the pump and the start of copper pipe. Will this work? Is there a better place to put it? Thanks.
I would look into changing the foot valve. If it still has the spring in it, there shouldn't be a hammer. I don't know what a hydrarester is, but it probably won't stop a hammer like that. I don't like check valves in the suction line for many reasons. And I don't know of any valve that was designed to go into a suction line to stop hammer.
bob...
The foot valve is not very old, maybe 4 years, and I was getting the plastic pipe slap when it was new. The Hydra-Rester is the name of the Sioux Chief Water Hammer Arrester. My problem seems to be when the copper pipe goes from being under suction to being under pressure after the pump stops.
Was this new check valve a plastic valve or a brass valve. And do you remember the name of the valve?
Are you certain there are no other valves in the suction line?
With a working check valve there should be no slap when the pump shuts off, even with a high vacuum. The more vacuum and less water being pumped, the closer the poppet is to it's seat.
bob...
It was a brass valve, but I don't know the name. There are no other valves in the line. The line consists of a foot valve at the end of a rigid plastic pipe that is connected to about 40' of 1" flex plastic pipe that goes under ground to my basement. This line is then connected to about 40' of 1" rigid copper pipe that is connected to about 5' of 1" flex plastic pipe that connects to the pump. The output of the pump is connected to the pressure tank with 3/4" galvanised pipe.
You do have a mix of different piping there. But I can't explain the hammer without thinking the footvalve is bad. I don't know what else could be causing it. Changing pipe types shouldn't really have anything to do with water hammer.
Although I don't like to do this, you could try to put a checkvalve in front of the pump. If the hammer goes away, you have fixed the problem. We'll never know why or how, but the hammer is still gone.
bob...
When you say put a check valve in front of pump, do you mean on the suction side or the pressure side? I would try and change the foot valve, but it is down in a well pit and not easy to do. What would be a good foot valve to use if I decide to try that? Thanks for your help.
There are many brand names. I use Boshart's valve and love it. There are other's that are just as good. Stay with brass not plastic.
bob...
I forgot to answer the other question. In the suction line always.
bob...
Bob, I tried the easiest fix first, which was to put a water hammer arrestor in the suction line at the well. This worked very well for about 6 cycles and then the arrestor failed. I guess it couldn't stand the vacuum. I then put a check valve in the suction line at the pump and that seems to be working great. Hope it continues and I think it will. Thanks for your help.
Gary
I am not sure what a waterhammer arrester is for the suction line of a pump, but my advice is put as few fittings as possible in a suction line as possible.
When you change the foot valve and remove the check valve, I think your problem will go away.
bob...
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