I have a terraced drip irrigation system that is a few stories high. I’d like to put an automatic (but passive) drain valve at the bottom, so that when the system isn’t pressurized, the valve opens up and drains the water out of the system tubing into a cistern. But when the system turns on again, the pressure closes the valve, and it waters like normal.
I don’t know what such a valve is called though. I have searched amazon and the web under many different search terms, but am not finding what I want.
One thought... Could I use an anti-siphon valve (installed backwards?) to do what I want?