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Pilot Valve Operation (Electric Models Only)
The main function of the pilot valve is to control the operation of the
main valve located in the base of the sprinkler body. The main valve is
operated by the release of water metered through the pilot valve when
it is activated either manually at the sprinkler or by the irrigation system
controller.
Another important function of the pilot valve is to regulate the water
pressure to the sprinkler nozzle. Pressure regulation compensates for
large variations within the system and maintains a constant pressure
for optimum sprinkler operation. The pilot valve is factory set to
regulate one of four pressure levels 50 psi (3.4 bar), 65 psi (4.5 bar),
80 psi (5.5 bar) or 100 PSI (6.9 bar).
Change the pilot valve operating pressure by loosening the thumb
screw that secures the selector lever. Position the selector lever to the
desired operating pressure and hand-tighten the nut. See Figure 10.
Troubleshooting __________________________________________________________________
Pilot Valve
PROBLEM
Sprinkler will
not turn on
Sprinkler will
not shut off
Sprinkler Mechanism
PROBLEM
Sprinkler won't rotate
Head sticks up
Poor distribution pattern
8
POSSIBLE CAUSE – CORRECTIVE ACTION
(a) No 24 VAC to solenoid assembly. (Electric Models)
– Measure voltage with a Digital Volt Meter (DVM). Check wiring and controller program.
– Refer to Controller Operating Instructions.
(b) Selector cam in "OFF" position.
– Set to "AUTO" position.
(c) Debris in pilot valve assembly.
– Disassemble and remove all debris. (See Servicing Pilot Valve page 12.)
(d) Insufficient pressure in controller supply line and/or sprinkler control tube. (N.C. Models)
– Check pressure.
(a) Constant 24 VAC from controller. (Electric Models)
– Check for voltage using a DVM. If voltage is present, disconnect wire.
If sprinkler closes, service controller. Refer to Controller Service Manual.
(b) Selector cam in manual "ON" position.
– Set to "AUTO" or "OFF" position.
(c) Debris in pilot valve assembly.
– Disassemble and remove all debris. (See Servicing Pilot Valve page 12.)
(d) Constant pressure from controller. (N.C. Models)
– Check pilot valve at controller for constant flow.
– Check elevation differential. Valve elevation should not exceed 0' above
controller elevation or 70' (21.3 m) below controller elevation.
POSSIBLE CAUSE – CORRECTIVE ACTION
(a) Debris wedged between stator and turbine.
– Remove obstruction.
(b) Drive assembly defective.
– Replace drive assembly.
(c) Nozzle base assembly defective.
– Replace nozzle base assembly.
(a) Dirt in riser assembly.
– Flush out. (See Flushing Procedure on page 12.)
(b) Damaged or missing return spring.
– Replace.
(c) Damaged riser.
– Replace.
(a) Nozzle plugged with debris.
– Clean or replace nozzle.
(b) Nozzle orifice damaged.
– Replace nozzle.
(c) Low operating pressure.
– Determine why system overloaded and correct.
Figure 10
100 PSI
(7.0 kg/cm
80 PSI
(5.6 kg/cm
(4.6 kg/cm
2
)
2
)
65 PSI
2
)
50 PSI (3.5 kg/cm
2
)
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