VALVE WON'T CLOSE | (a) | Leak in control tubing. |
(Hydraulic) |
| – 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. |
VALVE WON'T OPEN | (a) | Control (field) wires severed. |
(Electric) |
| – 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. |
VALVE WON'T OPEN | (a) | Plugged controller discharge line or discharge port in pilot valve. |
(Hydraulic) |
| – Verify by checking for discharge at discharge line when station is |
|
| activated. If no discharge, refer to Controller Service Manual. |
SPRINKLER WEEPING | (a) | Damaged or blocked valve seat. |
(Slow leak in valve) |
| – 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. |
SEVERAL VALVES ON DIFFERENT | (a) | Control tubing leak which lowers supply pressure to other stations. |
STATIONS FAIL TO CLOSE |
| – Turn controller from station to station until a station is reached where |
(Hydraulic) |
| 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. |
7
