Thermo Valve Oven, Operating Manual

Page: 44 / 62

Chapter 4
Troubleshooting
44 Operating Manual
Refer to the TRACE operations manual, Chapter 4 , Gases and Controls, for leak
test suggestions and the necessary hardware required to pressure check a
plumbing system.
Valve Switching
Valco valves contain a rotor that is turned by the actuator. This rotor channels the
gas between the various ports of the valve. If the rotor is not being switched
properly, a flow path may be partially or fully blocked, or leaks may occur
between valve ports.
Each valve contains a mechanical stop that should reach an extreme when the
valve is rotated in the clockwise or counterclockwise direction. Close inspection
of the valve will indicate if the valve is being switched to its limits, Figure 2-4.
Actuator pressure should be 420 Kpa (60psig) to 630 Kpa (90 psig).
Table 4-1. Leak Testing for Valves
Symptom Cause Remedy
Valve leaking between ports Defective rotor Replace rotor or valve
Valve leaking around rotor Valve rotor not seating
properly
Rotor Defective Tighten rotor
Replace Rotor in valve
Leaking out valve ports Ferrule not seating Replace ferrule
Table 4-2. Causes and Remedies for Improper Valve Switching
Cause Remedy
Low actuator line pressure Increase line pressure
Solenoid not actuating Verify timed event is set correctly
Check voltage at solenoid
Replace defective solenoid