I have a Grundfos pump about 35 feet down my well. It delivers just under 11 GPM (measured) at the shut off pressure of 70PSI. The 1" poly line runs about 50 feet outside the house and about 70 feet inside. I'm doing some re-plumbing and it would not be too difficult to add a water hammer arrestor just inside the house on that 1" line. The only check valve is in the pump. Think it would be worthwhile?
Water hammer arrestor midway to preserve pump's check valve?
- Thread starter Mowmow
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LLigetfa
DIYer, not in the trades
No. Arrestors need to be at the end of the line and the pressure tank at the end of the line is the best arrestor.
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If you are getting water hammer it is from the check valve slamming when the pump stops abruptly from 11 GPM, as the check is wide open. When using a Cycle Stop Valve the tank is being filled at 1 GPM, and the check valve is barely open and there is no water hammer when the pump shuts off. It is best to prevent water hammer and water hammer is hard to catch, even with an arrestor once it is in motion.
Thanks Valveman. Totally makes sense - that is what I was trying to describe. I just don't know how durable the pump's check valve is. I would think they are designed to handle their design total head and GPM combo, and wondered if adding an arrestor mid-stream might cut the effective hammer in half. I'm not noticing much at the tank end, but it's the pump end that I was interested in - whether it is noisy or not, less stress is less stress.
LLigetfa
DIYer, not in the trades
Water velocity is a big factor in water hammer. Larger pipe would help.
No. Why do you ask? Do you have a symptom?
No visible symptoms. Just a matter of: can I do something that might help at minimal cost. I recall seeing threads on this site that talk about check valve life. I'm aware of the cycle stop technology and am not ready to switch over to that.
Interesting point. Thanks.
Symptom would be audible for water hammer. You already have what constitutes a very very large water hammer arrestor, as LLigetfa pointed out. So a separate water hammer arrestor would do nothing, other than possibly giving somebody a chuckle. Like people doing a flash photo of the moon.
But while replumbing, show us a photo of the pipe from your well, the input to your pressure tank, your pressure gauge, drain valve, pressure switch, and chances are we will point out a suggested improvement.
But while replumbing, show us a photo of the pipe from your well, the input to your pressure tank, your pressure gauge, drain valve, pressure switch, and chances are we will point out a suggested improvement.
Then you are not ready to solve all the problems that go with a pressure tank only pump system, like water hammer for one.
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