Irritrol 2700 anti-siphon cover issue

I installed 4 new Irritrol 2700 valves at my home out here in Phoenix. One day I walked out and noticed that the anti-siphon cover have come off. I tightened all the cover assemblies, but one of them just will not stay on. When ever I turn on that zone, the sprinklers run for a second, and then the cover pops off again.

Any idea why this is happening? I would think that the pressure would not be so great as to make the cover burst off, but apparently that is what's happening.

Thanks!

http://www.irritrol.com/support/troubleshooting.html

I have never seen these valves, here we use a single double check valve for the entire system. In a quick reading of the description of these valves, they should work. The will handle up to 150 psi which is almost certainly far more than your city water supply delivers. I would suggest you contact the dealer where you purchased these and see if they are still warrantied or if there is a repair that can be done to them.

You might post a photo or two of the malfunction. It happens there are two variations of the 2700 series valves. It also happens that the vacuum breaker cover has a central "dust cover" section that can come loose without causing leaks.

Your problem sounds like something new.

Hello A46220,

I work for Irritrol tech Support Dept. I would be more than happy to explain any inquiries with the 2700 series anti-siphon valve and why the shield cap cover is popping off. Please call M-F, 7:30-3:30PM PST 1-800-634-8873, press #2 and then #7 and enter ext 3718.

Thank you,
Bill

Is this post why their tech support line has been down all last week?