The Gas-Lok is shipped ready to install, assembled as shown in Figure 1 (below). The impulse hole (A) is closed at the factory. Port #1 of the three-way solenoid valve connects to the outlet end of the valve body. Port #2 is connected on the job to the main gas line ahead of all automatic control valves. Tubing is supplied for this connection. Port #3 connects to the lower diaphragm chamber of the Governor.
The Gas-Lok operates as a true zero governor when the solenoid is energized, opening Port #1 and Port #3. This allows the outlet pressure to be referred to the main diaphragm chamber (B). When the electric circuit is broken by a control device, the Gas-Lok operates as a cut-off valve. Port #1 closes and Port #2 opens. This allows gas flow from the line to the lower diaphragm chamber. The resulting increase in pressure under the main diaphragm (B) holds the valve tightly shut.
The Gas-Lok zero governor is NOT an approved safety shut-off valve and should not be used to shut-off the main gas flow in the event of a flame failure. In this case, use a Manual Reset Valve (Refer to Bulletin 1101) to shut-off the main gas flow.