Water hammering when pressure pump runs

[Nigel Ellis]

Hi folks,

First time poster here. I’m looking for some help in addressing a water hammering issue. This is not a new issue - we bought the house a while ago and have always experienced some kind of hammering going on.

System setup:
* In-ground pump that fills a holding tank
* Pressure pump with two inline pressure tanks
* Taps off to the three supply pipes (feeding two houses and apartment)

When the pressure pump runs, we hear pipes banging pipes in the basement ceiling of one of the houses. Looking at the supply pressure entering the house I see it fluctuate widely while the hammering is going on. I recently repressurized the tanks to 48psi with pressure cut off set to ~50 - 52 psi.

I did some research and learned about check valves. Looking at my setup, I wasn’t able to find any check valves on the system. In particular after the pressure switch (base of tanks) and before the well meters. Also nothing inside the house either. Could this be the cause of the problem? If so where should I install the valve(s) and how many?

I’ve posted more details hires pictures of the setup at https://photos.app.goo.gl/XLVa5DsnQXfJx2uK6

Thanks for any help or suggestions,

Nigel.

 

[Valveman]

There is a check valve on the line just before it gets the the pressure gauge. There is also a pressure relief valve on top that could be dumping water somewhere? If both of those are working properly I am guessing the hammer is coming from too much air in the tank. You need 2-5 PSI less air than the cut-in pressure, not the cut out. If cut off is 50-52, the cut on should be 30 PSI and you need 25-28 PSI air in the tank.

 

[Sponsor]

 

[Nigel Ellis]

Thank you Cary, I appreciate the help.

For sure I've overcharged the pressure tanks - I was confused and thought the pressure should be 2 psi less than the cut-out not cut-in. I'll drain them and bleed some air out to see if that helps.

Thanks,
Nigel.

 

[Nigel Ellis]

Cary, I bled off the pressure down to 28psi and that seems to have fixed things! Thank you.

Nigel.

 

[Reach4]

Cary, I bled off the pressure down to 28psi and that seems to have fixed things! Thank you.

Nigel.

Glad things are working nicely.

What is that white tube that tees off right after the pump output? Are you injecting chlorine or H2O2 through there?

 

[Nigel Ellis]

Ah that tube - that's used for priming the pressure pump. It's basically a tube that's inserted to top of the holding tank just below the waterline. When the tap is open the tube will fill and prime the pressure pump if empty. Once primed the tap is closed.