I am using a master valve upstream of my branch line solenoids. It seems that the master and downstream solenoids shut off simultaneously, or, perhaps, the downstream solenoid shuts off first. This means that when the system is off there is high pressure between the master valve and the solenoids.
This isn't ideal for the case where the user has high water pressure, and (in Australia) when using 19mm poly pipe it can result in slow dripping leaks until the pressure releases. This pressure isn't present when the downstream solenoids are operating.
Additionally, I notice a hammering sound when the system starts up. I wonder if this is from two valves opening almost simultaneously?
Can I ask/suggest, if a better method of solenoid timing is:
For start of run: downstream solenoid 'on', wait 1 second, master valve 'on'
For change of zones: downstream solenoid of current zone 'off', wait 1 second, downstream solenoid of new zone 'on'
For end of run: master valve 'off', wait 1 second, downstream solenoid 'off'
Would that seem practical? I'm thinking of how to reduce stress on the components in the system.
It's a great product, by the way!