I have 4 Hardie Anti-siphon valves in my sprinkler system that are about 15 years old and one is leaking.
I was thinking of replacing them all, but unfortunately they are glued on and that means cutting and modifying and trying my patience.
I took the valve top off and it looks like the diaphragm is the problem as it is somewhat twisted and torn.

I thought of just finding a repair kit and replacing the diaphragm.
However, the diaphragm raises up a few centimeters and won't come out.
Seems there is another part below it that has to be taken off before the diaphragm will come up and out.

Does this mean the Anti-siphon valve will have to be removed from the water line anyway to do this?
HELP!!