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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

POSSIBLE CAUSE – CORRECTIVE ACTION

Sprinkler will 

(a) No 24 VAC to solenoid assembly. (Electric Models)

not turn on

– 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.

Sprinkler will 

(a) Constant 24 VAC from controller. (Electric Models)

not shut off

– 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.

Sprinkler Mechanism

PROBLEM

POSSIBLE CAUSE – CORRECTIVE ACTION

Sprinkler won't rotate

(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.

Head sticks up

(a) Dirt in riser assembly.

– Flush out. (See Flushing Procedure on page 12.)

(b) Damaged or missing return spring.

– Replace.

(c) Damaged riser. 

– Replace.

Poor distribution pattern

(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.

8

Figure 10

100 PSI

(7.0 kg/cm

2

)

80 PSI

(5.6 kg/cm

2

)

65 PSI

(4.6 kg/cm

2

)

50 PSI (3.5 kg/cm

2

)

Summary of Contents for DT35 Series

Page 1: ...ectory Flow Rate 15 50 GPM 56 8 189 3 LPM Trajectory Selectable 15 or 25 Arc full circle 360 or adjustable part circle 40 330 Recommended operating pressure 65 100 psi 4 5 6 9 bar Minimum pressure 40 psi 2 8 bar Maximum pressure 150 psi 10 3 bar Precipitation rate Minimum 0 46 hr 1 17 cm hr Maximum 0 63 hr 1 60 cm hr Inlet Size 1 25 mm NPT BSP or ACME Electric Valve in head Solenoid Inrush current...

Page 2: ...________________ DT55 Series Sprinkler Performance Data DT35 Series Sprinkler Performance Data Base Nozzle Set Nozzle Set Nozzle Set Nozzle Set Nozzle Set Nozzle Set Nozzle Set Nozzle Set Pressure 30 Plug 31 Yellow 32 Blue 33 Brown 34 Orange 35 Green 36 Gray 37 Black BIEGE YELLOW PLUG GREEN YELLOW YELLOW YELLOW YELLOW YELLOW YELLOW GREEN YELLOW GREEN GREEN GREEN GREEN psi Radius GPM Radius GPM Rad...

Page 3: ...Distance from Head 26 33 28 34 32 35 Nozzle PSI GPM 34 Nozzle 65 PSI 29 0 GPM 35 Nozzle 65 PSI 36 0 GPM 36 Nozzle 80 PSI 44 0 GPM Trajectory 15 25 15 25 15 25 A Radius 63 70 64 74 73 80 B Spray Height 6 14 7 15 8 17 C Distance from Head 35 39 36 43 40 45 Nozzle PSI GPM 37 Nozzle 80 PSI 47 0 GPM Trajectory 15 25 A Radius 72 85 B Spray Height 8 18 C Distance from Head 39 46 A B C DT35 Series Traject...

Page 4: ...ing Chart Table 1 for proper application Note Wire length data provided in Table 1 is the sum of the station and common wire legs See example in Figure 2 2 Attach control wires to solenoid leads using an approved waterproof splicing method CAUTION All wire splices and field connections must be waterproofed to prevent short circuit to ground and subsequent controller damage 4 A U T O ON OFF Figure ...

Page 5: ... air from the system lines during the filling process For best results do not compress air and then relieve it bleed the air continuously while filling the system 3 After water has filled all lines and all air is removed remove the quick coupler keys Table 3 Recommended System Fill Rate Table 2 Hydraulic Control Systems Maximum Distance Type of System From Controller Elevation Restrictions Normall...

Page 6: ...he turret counter clockwise until it stops The left stop indicates the fixed stop of the arc See Figure 4 3 Find the sprinkler right stop by rotating the turret clockwise until it stops See Figure 5 Note If the sprinkler is set at 360 full circle there will be no stop when turning clockwise 4 Adjust the arc while the turret is pointing at the right stop Hold the sprinkler riser firmly while pressi...

Page 7: ... position 2 Remove the cap retaining screw and cap 3 Using a 5 8 nut driver P N 995 99 turn the nozzle housing assembly left to select 15 trajectory as shown in Figure 8 Turn the nozzle housing assembly right to select 25 trajectory as shown in Figure 9 4 Install the cap making sure the top the nozzle housing is correctly nested in the cap 5 Install the cap retaining screw 6 Activate the sprinkler...

Page 8: ...tion 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 Sprinkler will a Constant 24 VAC from controller Electric Models not shut off Check for voltage using a DVM If voltage is present disconnect wire If sprinkler closes service controller Ref...

Page 9: ...r 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 th...

Page 10: ...he screen counterclockwise to remove 5 Remove the variable stator 16 from riser assembly 6 Loosen the drive assembly retaining screw 14 6 7 turns and pull the drive assembly 15 using a pair of pliers See Figure 12 Note Do not remove the retaining screw completely as it is easily misplaced CAUTION When removing or installing the drive assembly do not use the turbine to pull the drive assembly Use t...

Page 11: ... carrier as shown Locate position of communication tube in bottom of sprinkler body and orient insertion tool accordingly Insert tool straight down into sprinkler body aligning bosses on t handle with holes on sprinkler body flange When valve assembly clears vertical side wall ribs inside body pull up on snap ring release mechanism DT55 models only and press valve assembly into position Snap ring ...

Page 12: ...cessary and reassemble in reverse order Note Refer to Illustrated Parts Breakout Book form number 368 0044 for service part numbers Flushing Sprinkler ________________________________________________________________ 1 With sprinkler operating carefully step down on center of cap several times Water will flow around riser and flush out debris 2 Cycle sprinkler on and off several times to check for ...

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