2. The SOPV directs pressure from the main valve
inlet into the cover chamber of the hytrol valve, holding
it closed. This diverts high pressure through the ejector-
strainer into the cover chamber of the fueling valve,
holding it closed.
3. The SOPV also vents the cover chamber of the
defueling valve to the defueling line. With pressure
released from the cover chamber, the defueling valve
opens by virtue of its own weight and inverted design.
The defueling valve will have a controlled opening rate
produced by a restriction tube elbow located in the line
from the cover chamber.
Cla-Val Fuel/Defuel
Pressure-Setting Procedures
Procedures are the same for all pressure settings;
only the pressure will vary. This example is for a final
delivery pressure of 50 psi. The pressure-setting pro-
cedures are the following:
1. A pressure gauge must be installed in the line
between the fuel/defuel valve and the hose.
2. Remove adjusting screw housings for both
pressure-relief control valves and the pressure-reducing
control valve.
CAUTION
Do not turn these screws beyond the point
at which they become tight. Damage to the
internal parts of the valve may result.
3. Loosen all three jam nuts and gently screw the
adjusting screw on both pressure-relief control valves
all the way in.
4. Line up and pressurize the service system.
5. Unreel the hose and connect the nozzle to the
defuel main. (Use proper grounding procedures.)
6. Start the defuel pump.
7. Place the toggle switch to the ON position.
8. Slowly turn the adjusting screw on the pres-
sure-reducing control valve until the gauge in the deliv-
ery line reads 10 psi higher than the desired pressure (60
psi in this example).
9. Tighten the jam nut to lock the adjusting screw.
10. Slowly turn the adjusting screw of the defuel
valve’s pressure-relief control valve until the delivery
pressure gauge dips downward approximately 2 1/2 psi
(57 1/2 psi in this example).
NOTE
The defuel valve’s pressure-relief control
valve will be set 7 1/2 psi higher than delivery
pressure.
11. Tighten the jam nut to lock the adjusting screw.
12. Loosen the jam nut and slowly turn the adjust-
ing screw of the pressure-reducing control valve until
the delivery pressure drops to a point 5 psi above the
desired delivery pressure (55 psi).
13. Tighten the jam nut.
14. Slowly turn the adjusting screw of the fuel
valve’s pressure-relief control valve until the delivery
pressure gauge begins to dip downward approximately
2 1/2 psi (52 1/2 psi).
NOTE
The fuel valve’s pressure-relief control
valve will be set 2 1/2 psi higher than delivery
pressure.
15. Tighten the jam nut to lock the adjusting screw.
16. Loosen the jam nut and slowly turn the adjust-
ing screw of the pressure-reducing control valve until
the delivery pressure has dropped to the desired delivery
pressure (50 psi).
17. Tighten the jam nut to lock the adjusting screw.
18. Replace all adjusting screw housings.
19. Secure station.
Trouble-shooting Procedures
To do troubleshooting, you must completely un-
derstand the function of the Cla-Val. Before you actu-
ally make any mechanical adjustments, carry out the
following steps:
1. Be sure that the SOPV is operating when the
fueling switch is turned to the ON position and that it is
being deenergized when the switch is turned to the OFF
position. (This is commonly called a “click” test.)
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