Patent References 909985 1790467 1796201 3307633 3464497 3587746 Pressure relief valve Patent #: 4085765 InventorAssigneeApplicationNo. 271578 filed on 03/18/1999US Classes:169/22, Differential area169/17, Dry pipe169/20Pressure controlledExaminersPrimary: Weldon, KevinAssistant: Bocanegra, Jorge Attorney, Agent or FirmInternational ClassA62C 037/36AbstractIn the dry pipe sprinkler valve arrangement disclosed in the specification, a dry pipe sprinkler line is normally supplied with air at a pressure in a range from about 5 psi to about 20 psi and is connected through a check valve, a dry pipe valve and a manual control valve to a water supply line. The dry pipe valve has a clapper which is normally retained in the closed position by a latch member. An actuating valve having a diaphragm which receives air pressure from the sprinkler line on one side and engages an orifice to which water from the water supply is applied on the other side permits the latch member to release the clapper when the air pressure falls as a result of opening of a sprinkler in the sprinkler line. When the system is being reset after operation the latch is either automatically movable or manually movable by an external handle to restore the clapper to its seated position without requiring opening of the dry pipe valve housing. | |