Air Lock is used when it is required to automatically hold the air pressure in diaphragm chamber of the actuator, on the same level in an event of failure of air supply. When supply pressure drops below a preset value, the Air Lock Relay locks the air pressure in the diaphragm chamber of the actuator thereby holding the inner valve in one position, till the air supply is resumed.

Air Lock is used when it is required to automatically hold the air pressure in diaphragm chamber of the actuator, on the same level in an event of failure of air supply. When supply pressure drops below a preset value, the Air Lock Relay locks the air pressure in the diaphragm chamber of the actuator thereby holding the inner valve in one position, till the air supply is resumed.