Reverse Water Hammer from Sprinklers??

[TAHUSKER]

Hello:

I found a thread here from awhile back that discussed fixes for "reverse water hammer" caused by automatic sprinkler systems. I think I have the same issue . . . and I saw that one simpler solution might be to install a check-valve in the line. I know pretty much nothing about plumbing, and could use some additional detail as to what kind of valve I should look to get and exactly where this needs to be installed (picture, graphic, etc.). If anyone can help, I would be very grateful!

The issue started when I had to replace a couple of the original sprinkler manifold valves. Shortly after, we would hear a single, loud BANG! every time the sprinklers would kick on (definitely not when they stopped). I could ease the sound a bit by turning down the pressure to the manifold. Still does it a bit, though.

[LazyPup]

Water hammer can occur anytime there is a dramatic increase in line pressure. While it is most often associated with fast acting valves when they close, it can also occur when a fast acting valve opens the pressure in the line downstream from the valve changes rapidly.

For this reason the plumbing codes require a water hammer arrestor be installed in the near proximity of all fast acting valves, such as water closet fill valves, washing machine fill valves, ice maker fill valves and any solenoid operated valves such as those found on HVAC feed water sytems or lawn irrigation systems.

In most instances a backflow preventer or check valve is not sufficient because they cannot react fast enough to resolve the problem, however all irrigation systems are required to have a Vacuum breaker mounted at least 6" higher than the elevation of the highest sprinkler head on the system. The vacuum breaker should be sufficient to prevent water hammer.

[TAHUSKER]

I do have a vacuum breaker installed (and correctly it appears), but it's not preventing the water hammer. Would a "water hammer arrestor" possibly provide some help . . . or is that more for preventing the issue when the offending valve(s) turn off and not on?