| 摘要 |
<p>An actuator (150) is provided for a check valve (50), having particular utility in a dry fire control system. The check valve (50) is responsive to a drop in the system air pressure occasioned by opening of one or more sprinkler heads (88) in the fire control system. The movement of the actuator to its open position, establishes a water drain line (122) therethrough, while advantageously also opening a previously sealed vent outlet (397) 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.</p> |
