Patent ID: 6536740
Filing Date: 2003-03-25
Classification: F15B,F16K

Abstract:
A hydraulically actuated valve actuator, comprising:a spring housing including a bonnet for coupling said spring housing to a valve; said bonnet including a valve stem bore extending through said bonnet and a sealing means disposed around said valve stem bore for sealing a valve stem extending through said bonnet; said spring housing including an upper head and a packing gland, said upper head includes a counterbore therein to define a pressure chamber therein, said upper head and said packing gland sealingly engaging said spring housing to define an interior pressure chamber, said interior pressure chamber having a pressure responsive actuator piston disposed therein, an urging means disposed within said spring housing, said urging means urging said pressure responsive actuator piston between first and second positions; said pressure responsive actuator piston coupled to said valve stem by an adapter stem; said pressure responsive actuator piston including a piston and a spring retainer nut, said piston and said spring retainer nut separable to prevent ambient pressure acting within said pressure chamber on said pressure responsive actuator piston from loading said valve stem; and, said packing gland includes a raised inner face and pressure applied to said upper head pressure chamber urges said piston into contact with said spring retainer nut of said pressure responsive actuator piston and urges said adapter stem into contact with said raised inner face of said packing gland and said urging means to its first position.