air impact stops sprinkler valve from loading

[keep_it_real]

My sprinkler valve won't accept air when I open a slide valve. The sprinkler valve is set up in semi-auto configuration so air is coming in the top. I can actually reach in and feel the diaphragm but I can't move it because the pressure is pushing it down.

This set up actually worked until I put more holes in the slide valve so it would load faster. But now the little hole that lets air pass in the diaphragm somehow closes and won't let air through. It's bizarre.

It works around 20 psi but any higher than that and it stops working.

Has this happened to anyone and how did you fix it?

My best solution at this point is to fill the hole in the diaphragm with epoxy and drill a new hole through it.

[Lentamentalisk]

I am completely at a loss as to what you are doing. Diagram?

try unscrewing the sprinkler valve, to see if any air is actually coming out. I don't understand what you mean by not accepting air...

[keep_it_real]

Light blue is atmosphere
Dark blue is pressurized
air flows through the slide valve in one position
then it vents which fires the sprinkler valve in the other position

[Lentamentalisk]

well take it apart, as check to see if the hole is obstructed.

Are you saying that it will work at 20psi, meaning that the chamber will fill up to 20psi, and then it stops equalizing, and only the top portion fills up to a higher pressure? Or are you saying that it doesn't work if the inlet pressure from your tank is over 20psi? because the latter would make absolutely no sense.

again, just take it apart and check it out.

[CS]

Err... pop the little plastic guy in the equalization point out? If I recall correctly the area directly around the equalization area is raised to prevent tearing. So best bet would be to stick with that hole, and not make another.

[grumpy]

sprinkler valves were not designed to fill and fire from the same port, if you want to use the same port to fill and fire try a qev. they were designed for this.

[keep_it_real]

I have taken it apart and yes I did pop the little white guy out of the equalization hole. This hole is probably 2 or 3 mm wide. I don't see how it could just close up.

lentamentalisk: it works when the inlet pressure is at 20 psi. I'm guessing because there is not as much of an impact that somehow squishes the rubber together as say 40 psi. Yes it's very weird.

grumpy: I've done this before with an orbit water master so I know it works fine.

[Lentamentalisk]

try hooking it up, and then turning on the pump, raising it from 0 all the way up to 100 or what ever, and see what happens, rather than dumping 100 in all at once.

[noname]

You could always connect a hose from somewhere on top of the sprinkler valve to the chamber, with a check valve in between. You won't slow the sprinkler's actuation, but air will make it to the chamber.

[keep_it_real]

If I pump it slowly up to 50 psi it works fine. So it's almost definitely a problem with impact. I also tried putting a small piece of tubing inside the equalization hole to keep it open but that didn't work. I reopened the valve and the tubing had been pushed slightly out of the hole. My best guess is the diaphragm is bulging against the wall of the sprinkler valve.

noname: The air has to be loaded through the sprinkler valve because it pushes a piston forward. I could have an inlet right behind the piston but... I think I'll first try getting an orbit watermaster valve because I know they work. Here's the gun I'll be using it on.

edit: called it. the diaphragm does bulge against the side. I put a longer piece of metal tubing in the equalization hole slowly gets pushed back out and stops working.