What is wrong with your sprinkler system if water shoots out of your backflow relief valve when you first turn on the sprinkler water source at the beginning of the sprinkler season?
The unit must be installed 12 inches (300 mm) above ground and
no more than 30", check with local authorities. The RP assemblies
may spit out water of relief port for a variety of reasons so they
must have a floor drain if being installed inside a building. Some
of the reasons for spitting or flow from relief valve ports are if
they detect backflow, inlet/outlet pressure fluctuations, dirt, or
debris on first check valve or relief valve. Check trouble-shooting
guides. It is also recommended that a strainer be installed with a
RP device due to the sensitivity of the check valves and relief
valve ports to dirt or debris