I have been working on a system that has a 100 ft well with a 1 hp submersible pump set at about 80 ft and water level at about 30 ft.
The pump is a 10 gpm pump. Someone prior to me had moved the bladder tanks to the garage area about 100 ft from the well head. The pressure switch is located at the well head and is screwed into a 1" check valve. I was called to this job to replace the pump. About 30 ft down in the well caseing is a 1" cycle stop valve. There are two 30 gal bladder tanks at the garage that are hooked up in series with a filter installed near them on the well head incomming line before the tanks. I installed a new pump and pressure switch. I have a lot of air hammer that causes the pressure switch to turn on and off rapidly. When I installed the new pump I removed the csv. The air hammer was so bad that the system would not pressure up at all. The pressure switch would just turn on and off rapidly. I reinstalled the csv by the advise of an old time well man and it slowed down the air hammer. When the pressure would get up to the cut off of 60 psi it would not air hammer when it shut off but when I drained down the system to the start up pressure of 40 psi the air hammer would start and it would not pressure up until I held the points shut for a few seconds to stop the air hammer. I installed a check valve near the bladder tanks and that made the problem worse as a sprinkler line is teed off the main line from the well head to the tanks. I removed the check valve at the tanks because I coulden't get anything to work right then. The check valve did not help with the air hammer anyway.

It seems if I set the start pressure at 45 lbs the air hammer is not present when it the pump starts but if I go any lower the air hammer is there. When I have the start pressure at 45 lbs then the cut-out pressure is 65 lbs and I was not willing to wait long enough to see if the pump would ever cut off at 65 lbs. I don't beleive it will ever cut off because the csv is rated for 60 lbs. I have never had any experience with a csv valve, all I know is it takes at least an hour for the pump to pump the system up to 55 lbs with no water being used.
I am starting to think that the only solution is to move the pressure switch to connect between the two bladder tanks and remove the csv from the well riser. I think the csv was originally installed to increase the life of the pump but it seems that at the same time, electricity and pressure over 60 lbs is sacrificed to try and get more life out of the pump. I also think that the excessive pump running has caused the pump that I just replaced to only last 5 years.
Please let me know if you think my solution is right or if you have a better idea, please let me know.

Brian Janak
bjanak@suddenlink.net