Abstract: A low pressure actuator for use in a dry, low-pressure, pressurized-gas, fire control and suppression sprinkler system for delivering an extinguishing liquid to a fire, wherein there is a system gas pressure of up to about 20 psi and an extinguishing liquid supply pressure of up to about 160 psi is disclosed. When actuated by a rapid fall in the system gas pressure, the device allows liquid to flow through to a sprinkler check valve, which, in turn, is actuated and provides liquid flow for distribution through a piping system to a plurality of interconnected sprinklers.

Abstract: An actuator is provided for a check valve, having particular utility in a dry fire control system. The check valve is responsive to a drop in the system air pressure occasioned by opening of one or more sprinkler heads in the fire control system. The movement of the actuator to its open position, establishes a water drain line therethrough, while advantageously also opening a previously sealed vent outlet for the pressurized air within the actuator. The seal for the vent outlet may be manually adjustable to compensate for manufacturing tolerances. The actuator may respond to either the magnitude of system air pressure drop, or the rate of system air pressure drop.

Abstract: An actuator is provided for a check valve, having particular utility in a dry fire control system. The check valve is responsive to a drop in the system air pressure occasioned by opening of one or more sprinkler heads in the fire control system. The movement of the actuator to its open position, establishes a water drain line therethrough, while advantageously also opening a previously sealed outlet for the pressurized air within the actuator. The actuator may respond to either the magnitude of system air pressure drop, or the rate of system air pressure drop.

Abstract: A low differential check valve is provided for a fire control system, having particular adaptability in a dry system. The check valve is maintained in its closed position by a latch which is controlled by a plunger. The plunger is activated, and moved to release the latch, upon the sensing of drop in system air pressure by a higher differential mechanism external of the check valve. The check valve may then be reset, with its clapper moved to its closed condition, without requiring internal access of the check valve to release a clapper latch.