Hello,
2 of the zones (zones 1&2) in my 5 zone irrigation system always hammer when the zones shut off. The other 3 zones work perfectly. The pvc pipes the that go to zone 1&2 go out of the manifold valve box underground. About 4 feet away they both come out of the ground, and into the wall of the garage and travel up (8ft) along the rafters to the opposite side of the garage (22ft). Then back down (8ft) and through the wall back to the exterior again at which point both the pipes go into the ground once more. Could this be the cause of the hammering? None of the other zones go up aboveground like that except for the sprinkler heads (and even then they don't go so high). With out having to run the pipes underground is there anything I can do to stop the water hammer? I should also mention. The water pressure is 80psi, the pipes are 3/4" and the system doesn't have a pump.

Thanks

This post was edited by diabolic812 on Mon, Dec 8, 14 at 4:55