Crown GLT-20 Installation & Operation Manual page 17

Gas Fired Steam Tilting Kettles
Re-Establishing Vacuum
Periodically check pressure gauge when kettle is cold. Reading should be in green vacuum zone (below 0 psi). Otherwise
air is present and proper heating will not occur. Use the following procedure to remove air and re-establish vacuum:
With the kettle empty, turn the thermostat knob to the highest temperature. When the temperature pilot light goes off, open
air vent nut one (1) full turn for 20 seconds and then close and tighten the nut. This should remove the air and any loss in
performance should return.
Should the kettle fail to maintain a vacuum after repeated attempts to establish vacuum, further checks should be made to
see if the pressure relief valve is leaking or if there are any leaks in the pressure relief valve piping, copper lines going to
the pressure switch, pressure gauge or thermostat fitting.
Under normal operating conditions a "try lever test" should be performed every two months. Under severe service
conditions, or if corrosion and/or deposits are noticed within the valve body, testing must be performed more often.
A "try lever test" should also be performed at the end of any non-service period.
Hot, high pressure fluid may be discharged from body drain and vent during "try lever" test.
Test at, or near, half of the operating pressure by holding the test lever fully open for at least two seconds to flush
the valve seat free of sediment and debris. Then release lever and allow the valve to snap shut.
If lift lever does not activate, or there is no evidence of discharge, turn off equipment immediately and contact a
licensed contractor or qualified service personnel.
INSTALLATION & OPERATION MANUAL 10070 REV 0 (04/21)
Safety Valve Maintenance and Testing
Care must be taken to avoid any bodily contact.
High sound levels may be experienced during "try lever" test.
Wear proper safety equipment and exercise extreme care!
CAUTION
CAUTION
CAUTION
Service
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