Filter
Top Products
Page 4-4
As this is taking place, the thermostat also opens the main gas line, and provides gas to the safety
valve (see Figure 4-6). As soon as the safety valve is hydraulically opened by the signal from the
sensing bulb, gas is released from the safety valve to the oven burner, and ignited by the heater
pilot flame. NOTE: If the heater pilot flame is not available to heat the safety valve sensing bulb,
the safety valve will not open, and gas can not enter the oven.
Gas Flows Out
Orifice Hood
Gas Inlet
(From Thermostat)
Heater Flame
Heats Sensor
Valve Opens & Gas
Flows To Oven Burner
Pressure Forces
Contact Against
Switch & Opens Valve
Safet
y
Valve
Gas Safety Valve Open
Figure 4-6
Gas Safety Valve Closed
When the oven reaches the selected temperature, the sensing bulb for the thermostat closes the
thermostat gas lines and reduces the heater pilot flame back to a smaller “standing pilot” flame.
With no heater pilot flame, the sensing bulb for the safety valve cools, closes the safety valve, (see
Figure 4-7), stops the gas supply to the oven burner, and eliminates the flame. This cycling will
continue for the duration of the cooking cycle.
Orifice Hood
Heater Sensing
Bulb & Capillary Tube
Gas Inlet
(From Thermostat)
Cold Sensor
Valve Closed
No Gas Flow
Safety Valve
Figure 4-7