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Main Valve
PROBLEM
Valve won't close
(Electric )
Valve won't close
(Hydraulic)
Valve won't open
(Electric)
Valve won't open
(Hydraulic)
Sprinkler Weeping
(Slow leak in valve)
Several valves on different
stations fail to close
(Hydraulic)
POSSIBLE CAUSE – CORRECTIVE ACTION
(a) Continuous 24 VAC to sprinkler.
– Check controller for voltage source.
(b) Leak in pilot valve assembly.
– Replace pilot valve assembly.
(c) Plugged supply screen on piston.
– Clean or replace screen.
(d) Manual control selector on pilot valve assembly turned to "ON" position.
– Turn to "AUTO" position.
(e) Plunger movement restricted.
– Inspect and clean or replace.
(f) Valve cylinder misaligned with sprinkler body communication tube.
– Remove valve assembly and install correctly.
(g) Foreign object keeping valve from seating.
– Remove, clean and check valve for damage. Replace if necessary.
(h) Damaged piston seal or piston assembly.
– Replace valve assembly.
(a) Leak in control tubing.
– Isolate and repair.
(b) Pilot valve leak in controller.
– Confirm by observing constant dripping from discharge line of controller.
Refer to Controller Service Manual.
(c) Valve cylinder misaligned with sprinkler body communication tube.
– Remove valve assembly and install correctly.
(d) Foreign object keeping valve from seating.
– Remove, clean and check valve for damage. Replace if necessary.
(e) Damaged piston seal or piston assembly.
– Replace valve assembly.
(a) Control (field) wires severed.
– Isolate and repair.
(b) No power to controller.
– Establish controller power.
(c) No power from controller to solenoid.
– Check for blown fuse and replace.
(d) Manual control selector on pilot valve assembly turned to "OFF" position.
– Turn to "AUTO" position.
(e) Pilot valve solenoid inoperative.
– Remove and replace.
(f) Pilot valve plunger movement restricted.
– Inspect, clean and/or replace.
(g) No supply from main valve.
– Debris in control tube, main valve assembly and/or communication
passages in body. Flush thoroughly.
(a) Plugged controller discharge line or discharge port in pilot valve.
– Verify by checking for discharge at discharge line when station is
activated. If no discharge, refer to Controller Service Manual.
(a) Damaged or blocked valve seat.
– Remove blockage and, if necessary, replace valve assembly.
(b) Damaged piston seal or piston assembly.
– Replace valve assembly.
(c) Low pressure on supply line .
– Check for low pressure reason and correct.
(d) Elevation of normally closed sprinkler exceeds 75' (22.9 m) differential.
(a) Control tubing leak which lowers supply pressure to other stations.
– Turn controller from station to station until a station is reached where
only valves on that station stay open. The leak would be in the tubing
on that station. Isolate and repair.
(b) Leak in supply line to controller.
– Verify by checking pressure in all control lines.
(c) Leak in controller pilot valve.
– Verify by constant discharge from controller.
(d) Plugged supply line filter.
– Replace filter if more than 3 psi (0.21 bar) differential exists.
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