Loud Noise switching between spray and rotary heads

[Spaceboy]

I've searched the site and believe I might have found a few solutions, but none seem to be for the exact problem I'm experiencing so I thought I would post on here in case somebody else had this issue.

I recently had an irrigation system installed on my 1/4 acre lot. It was done by a reputable sprinkler system guy, and all parts Hunter - so PGP Rotary heads, Controller etc.

Everything is working great, however every time my sprinkler cuts over from zone 1 to zone 2 it makes a knocking noise in the pipes near where they put tied into my main to run the backflow. The nose lasts < 3 seconds but it is fairly loud, and worrisome to me.

This only occurs between the switch of Zone 1 and another Zone. So, if I turn off Zone 2, I would hear it between the switch of Zone 1 and Zone 3 instead.

Zone 1 is setup so it's all of my bed spray heads and all other zones are made up of rotary PGP heads. If I turn off Zone 1 (so no spray heads) I do not get the knocking running the system etc.

Anybody have any advice? I read where it might possibly be fixed by switching it so my spray zone is my last zone ran by my controller but have no clue how you can do that.

I wanted to try to do some digging before I called up the person who did the installation.

Any advice is appreciated.

Thanks

[msgale]

it's probably the rapid turn off of zone 1, the flowing water comes to a quick stop, producing the noise.
to fix it, you need to add an air chamber to the piping before the shut off valve for zone one. commercially available, or you plumb in a dead-end piece of pipe physcially above your supply pipe, so it doesn't fill w water,but becomes an air cushioin to absorb the force of the flowing water.

[Mr_Pike]

Would you describe the noise as Banging? Like pipes shaking banging, or a loud ticking that gets progressively slower?

[Wet_Boots]

Try making the bed zone the last one to water.