Operator for valves or the like

Claim 2

Apparatus for operating a valve closure member or the like by means of energy derived from a flowline subject to fluid pressure variations, comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for moving the closure member between alternate positions in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each having an end for connection with the flowline, means including four-way valve means connected between said first and second conduit means and said first and second responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its end for connection to the flowline and the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its end for connection to the flowline and its connection to the accumulator to prevent flow from the accumulator to the flowline, whereby fluid pressure in the accumulator tends to approach the upper extreme value of said pressure variations to provide a differential between the accumulator pressure and another value of the flowline pressure for use in moving the actuator.

Claim 3

Apparatus of the character defined in claim 1, wherein said four-way valve means includes a shiftable member having oppositely reacting fluid responsive surfaces, and the means for moving the four-way valve means includes means for supplying fluid pressure to one of said surfaces to urge the member to one position, the other of said surfaces being subject to fluid pressure of the environment in which the four-way valve means is disposed to urge said member to the other position, and spring means engaging said member to also urge it to said other position.

Claim 4

In combination with a valve or the like having a flowway therethrough fluidly connectable in a flowline subject to fluid pressure variations, and a closure member movable between positions for opening and closing the flowway, an operator comprising an actuator having first and second oppositely reaching fluid pressure responsive surfaces and means for so moving the member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means connecting with the flowway, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connection to the flowway and the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connection to the flowway and the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connection to the flowway and its connection to the accumulator to prevent flow from the accumulator to the flowway, whereby fluid pressure in the accumulator tends to approach the upper extreme value of said pressure variations to provide a differential between the accumulator pressure and another value of the flowline pressure for use in moving the actuator.

Claim 5

In combination with a valve or the like having a flowway therethrough fluidly connectable in a flowline subject to fluid pressure variations, and a closure member movable between positions for opening and closing the flowway, an operator comprising an actuator having first and second oppositely reaching fluid pressure responsive surfaces and means for so moving the member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means connecting with the flowway, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connection to the flowway and the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connection to the flowway and the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connection to the flowway and its connection to the accumulator to prevent flow from the accumulator to the flowway, whereby fluid pressure in the accumulator tends to approach the upper extreme value of said pressure variations to provide a differential between the accumulator pressure and another value of the flowline pressure for use in moving the actuator.

Claim 6

The combination of claim 3, wherein the first and second conduit means connect with the flowway on opposite sides of the closure member.

Claim 7

Apparatus fOr operating a valve closure member or the like by means of energy derived from a flowline subject to fluid pressure variations, comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for moving the closure member between alternate positions in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each having an end for connection with the flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, first and second accumulators, means connecting said first accumulator to the first conduit means intermediate its end for connection to the flowline and the four-way valve means, means connecting said second accumulator to the second conduit means intermediate its end for connection to the flowline and the four-way valve means, one-way valve means arranged in the first conduit intermediate its end for connection to the flowline and its connection to the first accumulator to prevent flow from the first accumulator to the flowline, and one-way valve means in the second conduit intermediate its end for connection to the flowline and its connection to the second accumulator to prevent flow from the flowline to the second accumulator, whereby fluid pressure in one accumulator tends to approach one extreme value and fluid pressure in the other accumulator tends to approach another extreme value of said pressure variations, the difference between said accumulator pressures providing said differential pressure for use in moving the actuator.

Claim 8

Apparatus fOr operating a valve closure member or the like by means of energy derived from a flowline subject to fluid pressure variations, comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for moving the closure member between alternate positions in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each having an end for connection with the flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, first and second accumulators, means connecting said first accumulator to the first conduit means intermediate its end for connection to the flowline and the four-way valve means, means connecting said second accumulator to the second conduit means intermediate its end for connection to the flowline and the four-way valve means, one-way valve means arranged in the first conduit intermediate its end for connection to the flowline and its connection to the first accumulator to prevent flow from the first accumulator to the flowline, and one-way valve means in the second conduit intermediate its end for connection to the flowline and its connection to the second accumulator to prevent flow from the flowline to the second accumulator, whereby fluid pressure in one accumulator tends to approach one extreme value and fluid pressure in the other accumulator tends to approach another extreme value of said pressure variations, the difference between said accumulator pressures providing said differential pressure for use in moving the actuator.

Claim 9

Apparatus of the character defined in claim 5, wherein each four-way valve means includes a shiftable member having oppositely reacting fluid responsive surfaces, and said means for moving the four-way valve means includes means for supplying fluid pressure to one of said surfaces to urge the member to one position, the other of said surfaces being subject to fluid pressure of the environment in which the four-way valve means is disposed to urge said member to the other position, and spring means engaging said member to also urge it to said other position.

Claim 10

In combination with a valve or the like having a flowway therethrough connectable in a flowline subject to fluid pressure variations, and a closure member movable between positions opening and closing the flowway, an operator comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving the member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means connecting with the flowway, means including four-way valve means connected between said first and second conduit means and first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, a first accumulator connected to the first conduit means intermediate its connection to the flowway and the four-way valve means, a second accumulator connected to the second conduit means intermediate its connections to the flowway and the four-way valve means, one-way valve means in the first conduit intermediate its connections to the flowway and to the first accumulator to prevent flow from the first accumulator to the flowway, and one-way valve means in the second conduit intermediate its connections to the flowway and to the second accumulator to prevent flow from the flowway to the second accumulator, whereby fluid pressure in one accumulator tends to approach one extreme value and fluid pressure in the other accumulator tends to approach another extreme value of said pressure variations, the difference between said accumulator pressures providing said differential for use in moving the actuator.

Claim 11

In combination with a valve or the like having a flowway therethrough connectable in a flowline subject to fluid pressure variations, and a closure member movable between positions opening and closing the flowway, an operator comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving the member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means connecting with the flowway, means including four-way valve means connected between said first and second conduit means and first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, a first accumulator connected to the first conduit means intermediate its connection to the flowway and the four-way valve means, a second accumulator connected to the second conduit means intermediate its connections to the flowway and the four-way valve means, one-way valve means in the first conduit intermediate its connections to the flowway and to the first accumulator to prevent flow from the first accumulator to the flowway, and one-way valve means in the second conduit intermediate its connections to the flowway and to the second accumulator to prevent flow from the flowway to the second accumulator, whereby fluid pressure in one accumulator tends to approach one extreme value and fluid pressure in the other accumulator tends to approach another extreme value of said pressure variations, the difference between said accumulator pressures providing said differential for use in moving the actuator.

Claim 12

The combination of claim 7, wherein the first and second conduit means connect with the flowway on opposite sides of the member.

Claim 13

For use with first and second flowlines, the pressure in said second flowline being subject to variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the second flowline and to the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connections to the second flowline and to the accumulator whereby fluid pressure in the accumulator tends to approach one extreme value of pressure variations in said second flowline to provide a differential between the accumulator pressure for use in moving the actuator.

Claim 14

For use with first and second flowlines, the pressure in said second flowline being subject to variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the second flowline and to the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connections to the second flowline and to the accumulator whereby fluid pressure in the accumulator tends to approach one extreme value of pressure variations in said second flowline to provide a differential between the accumulator pressure for use in moving the actuator.

Claim 15

For use with first and second flowlines, the pressure in said first flowline being subject to variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross first conduit means connectable to the first flowline, second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connections to the first flowline and to the accumulator, whereby fluid pressure in the accumulator tends to approach one extreme value of said pressure variations in the first flowline to provide a differential between the accumulator pressure and pressure in the second flowline for use in moving the actuator.

Claim 16

For use with first and second flowlines, the pressure in said first flowline being subject to variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross first conduit means connectable to the first flowline, second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connections to the first flowline and to the accumulator, whereby fluid pressure in the accumulator tends to approach one extreme value of said pressure variations in the first flowline to provide a differential between the accumulator pressure and pressure in the second flowline for use in moving the actuator.

Claim 17

For use with first and second flowlines, the pressure in said second flowline being subject to variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions for opening and closing the valve, anD an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first conduit means connectable to the first flowline, second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the second conduit means intermediate its connections to the second flowline and to the four-way valve means, and one-way valve means arranged in the second conduit means intermediate its connections to the second flowline and to the accumulator, whereby fluid pressure in the accumulator tends to approach one extreme value of pressure variations in said second flowline to provide a differential between the accumulator pressure and pressure in the first flowline for use in moving the actuator.

Claim 18

For use with first and second flowlines, the pressure in said second flowline being subject to variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions for opening and closing the valve, anD an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first conduit means connectable to the first flowline, second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the second conduit means intermediate its connections to the second flowline and to the four-way valve means, and one-way valve means arranged in the second conduit means intermediate its connections to the second flowline and to the accumulator, whereby fluid pressure in the accumulator tends to approach one extreme value of pressure variations in said second flowline to provide a differential between the accumulator pressure and pressure in the first flowline for use in moving the actuator.

Claim 19

For use with first and second flowlines subject to fluid pressure variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions for opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first conduit means connectable with each flowline, second conduit means connectable with one of said flowlines, means including four-way valve means connected between said first and second conduit means and said pair of pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with said second conduit means, and connecting the second surface with the first conduit means and the first surface with said second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, and a pair of one-way valve means each being disposed in the first conduit means intermediate its connections to the accumulator and each of its connections to the flowline and arranged so that fluid pressure in the accumulator tends to approach an extreme value of pressure variations in said first and second flowlines to provide a differential between the accumulator pressure and pressure in said one flowline to which the second conduit means is connected for use in moving the actuator.

Claim 20

For use with first and second flowlines subject to fluid pressure variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions for opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first conduit means connectable with each flowline, second conduit means connectable with one of said flowlines, means including four-way valve means connected between said first and second conduit means and said pair of pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with said second conduit means, and connecting the second surface with the first conduit means and the first surface with said second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, and a pair of one-way valve means each being disposed in the first conduit means intermediate its connections to the accumulator and each of its connections to the flowline and arranged so that fluid pressure in the accumulator tends to approach an extreme value of pressure variations in said first and second flowlines to provide a differential between the accumulator pressure and pressure in said one flowline to which the second conduit means is connected for use in moving the actuator.

Claim 21

For use with first and second flowlines subject to fluid pressure variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions for opening and closing the valve, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connectable with both flowlines, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, anD connecting the second surface with the first conduit means, and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, a first accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a second accumulator connected to the second conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a pair of one-way valve means each being disposed in the first conduit means intermediate the first accumulator and each flowline to prevent flow from the first accumulator to the flowlines, and a pair of one-way valve means each being disposed in the second conduit means intermediate the second accumulator and each flowline to prevent flow from the flowlines to the second accumulator, said one-way valve means being arranged so that fluid pressure in each accumulator tends to approach an extreme value of pressure variations in said flowlines to provide said differential for use in moving the closure member.

Claim 22

For use with first and second flowlines subject to fluid pressure variations, apparatus comprising a valve having a flowway connectable in the first flowline and a closure member movable between positions for opening and closing the valve, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connectable with both flowlines, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, anD connecting the second surface with the first conduit means, and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, a first accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a second accumulator connected to the second conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a pair of one-way valve means each being disposed in the first conduit means intermediate the first accumulator and each flowline to prevent flow from the first accumulator to the flowlines, and a pair of one-way valve means each being disposed in the second conduit means intermediate the second accumulator and each flowline to prevent flow from the flowlines to the second accumulator, said one-way valve means being arranged so that fluid pressure in each accumulator tends to approach an extreme value of pressure variations in said flowlines to provide said differential for use in moving the closure member.

Claim 23

For use with first and second flowlines subject to fluid pressure variations, apparatus comprising a valve having a flowway connectable in the first flowline and a member movable between positions for opening and closing the flowway, a second valve having a flowway connectable in the second flowline and a member movable between positions for opening and closing the flowway, and operators for the valves comprising a pair of actuators each having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving one of the closure members in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connectable with both flowlines, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces of each actuator for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means, and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, a first accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a second accumulator connected to the second conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a pair of one-way valve means each being disposed in the first conduit means intermediate the first accumulator and each flowline to prevent flow from the first accumulator to the flowlines, and a pair of one-way valve means each being disposed in the second conduit means intermediate the second accumulator and each flowline to prevent flow from the flowlines to the second accumulator, said one-way valve means being arranged so that fluid pressure in each accumulator tends to approach an extreme value of pressure variations in said flowlines to provide said differential for use in moving the closure members.

Claim 24

For use with first and second flowlines subject to fluid pressure variations, apparatus comprising a valve having a flowway connectable in the first flowline and a member movable between positions for opening and closing the flowway, a second valve having a flowway connectable in the second flowline and a member movable between positions for opening and closing the flowway, and operators for the valves comprising a pair of actuators each having first and second oppositely reacting fluid pressure responsive surfaces and means for so moving one of the closure members in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connectable with both flowlines, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces of each actuator for movement between alternate positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means, and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, a first accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a second accumulator connected to the second conduit means intermediate its connections to the first flowline and to the four-way valve means and its connections to the second flowline and to the four-way valve means, a pair of one-way valve means each being disposed in the first conduit means intermediate the first accumulator and each flowline to prevent flow from the first accumulator to the flowlines, and a pair of one-way valve means each being disposed in the second conduit means intermediate the second accumulator and each flowline to prevent flow from the flowlines to the second accumulator, said one-way valve means being arranged so that fluid pressure in each accumulator tends to approach an extreme value of pressure variations in said flowlines to provide said differential for use in moving the closure members.

Claim 25

For use with first and second flowlines, said first flowline being subject to pressure variations, apparatus comprising a valve having a flowway and a closure member movable between positions opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first conduit means connectable to the first Flowline, second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connections to the first flowline and to the accumulator, whereby fluid pressure in the accumulator tends to approach one extreme value of pressure variations in the first flowline to provide a differential between the accumulator pressure and pressure in the first flowline for use in moving the actuator.

Claim 26

For use with first and second flowlines, said first flowline being subject to pressure variations, apparatus comprising a valve having a flowway and a closure member movable between positions opening and closing the flowway, and an operator for the valve comprising an actuator having first and second oppositely reacting fluid responsive surfaces and means for so moving the closure member in response to the reaction of said surfaces to pressure differential thereacross, first conduit means connectable to the first Flowline, second conduit means connectable to the second flowline, means including four-way valve means connected between said first and second conduit means and said first and second pressure responsive surfaces for movement between positions connecting the first surface with the first conduit means and the second surface with the second conduit means, and connecting the second surface with the first conduit means and the first surface with the second conduit means, means for moving the four-way valve means between said alternate positions, an accumulator connected to the first conduit means intermediate its connections to the first flowline and to the four-way valve means, and one-way valve means arranged in the first conduit means intermediate its connections to the first flowline and to the accumulator, whereby fluid pressure in the accumulator tends to approach one extreme value of pressure variations in the first flowline to provide a differential between the accumulator pressure and pressure in the first flowline for use in moving the actuator.

Claim 27

For use with a flowline, apparatus comprising a valve having a flowway therethrough fluidly connected in the flowline and a closure member movable between positions for opening and closing the flowway, means for selectively restricting the flowline at a remote point downstream of the valve for causing pressure variations therein, and an operator for the valve including an operator for the valve indicating an actuator having a pair of oppositely reacting fluid pressure responsive surfaces and means for moving the closure member of the valve between alternate positions in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connected with the flowway, four-way valve means connected between said first and second conduit means and said pair of pressure responsive surfaces for movement between alternate positions connecting said one surface with the first conduit means and said other surface with said second conduit means, and connecting said other surface with the first conduit means and said one surface with said second conduit means, an accumulator connected to the first conduit means, one-way valve means in the first conduit means intermediate its connections to the flowway and the accumulator, the fluid pressure in the accumulator tending to approach one extreme value of said pressure variations to provide a differential between the accumulator pressure and another value of the flowline pressure for use in moving the closure member, means urging the four-way valve means to one of its alternate positions, pressure responsive means urging the said four-way valve means to its other alternate position, and means for connecting the pressure responsive means with the flowline downstream of the closure member, whereby reduction of pressure in said downstream portion of the flowline will cause the actuator to close the valve.

Claim 28

For use with a flowline, apparatus comprising a valve having a flowway therethrough fluidly connected in the flowline and a closure member movable between positions for opening and closing the flowway, means for selectively restricting the flowline at a remote point downstream of the valve for causing pressure variations therein, and an operator for the valve including an operator for the valve indicating an actuator having a pair of oppositely reacting fluid pressure responsive surfaces and means for moving the closure member of the valve between alternate positions in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connected with the flowway, four-way valve means connected between said first and second conduit means and said pair of pressure responsive surfaces for movement between alternate positions connecting said one surface with the first conduit means and said other surface with said second conduit means, and connecting said other surface with the first conduit means and said one surface with said second conduit means, an accumulator connected to the first conduit means, one-way valve means in the first conduit means intermediate its connections to the flowway and the accumulator, the fluid pressure in the accumulator tending to approach one extreme value of said pressure variations to provide a differential between the accumulator pressure and another value of the flowline pressure for use in moving the closure member, means urging the four-way valve means to one of its alternate positions, pressure responsive means urging the said four-way valve means to its other alternate position, and means for connecting the pressure responsive means with the flowline downstream of the closure member, whereby reduction of pressure in said downstream portion of the flowline will cause the actuator to close the valve.

Claim 29

Apparatus of the character defined in claim 16, wherein the four-way valve means includes means connecting said conduit means with said pressure responsive surfaces, in said one alternate position of said four-way valve means, to move the closure member to flowline closing position in response to a predetermined drop in flowline pressure.

Claim 30

Apparatus of the character defined in claim 16, wherein the means urging the four-way valve means to said one position comprises spring means and means responsive to the fluid pressure of the environment surrounding the four-way valve means.

Claim 31

Apparatus of the character defined in claim 18, wherein the first and second conduit means connect with the valve flowway on opposite sides of the closure member, respectively.

Claim 32

For use with a flowline, apparatus comprising a valve having a flowway therethrough fluidly connected in the flowline and a closure member movable between positions for opening and closing the flowway, means for selectively restricting the flowline at a remote point downstream oF the valve for causing pressure variations therein, and an operator for the valve including an actuator having a pair of oppositely reacting fluid pressure responsive surfaces and means for moving the closure member of the valve between alternate positions in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connected with the flowway, four-way valve means connected between said first and second conduit means and said pair of pressure responsive surfaces for movement between alternate positions connecting one surface with the first conduit means and the other surface with said second conduit means, and connecting said other surface with the first conduit means and said one surface with said second conduit means, means urging the four-way valve means to one of its alternate positions, pressure responsive means urging the said four-way valve means to its other alternate position, and means for connecting the pressure responsive means with the flowline downstream of the closure member and upstream of the restricting means, whereby reduction of pressure in said downstream portion of the flowline will cause the actuator to close the valve.

Claim 33

For use with a flowline, apparatus comprising a valve having a flowway therethrough fluidly connected in the flowline and a closure member movable between positions for opening and closing the flowway, means for selectively restricting the flowline at a remote point downstream oF the valve for causing pressure variations therein, and an operator for the valve including an actuator having a pair of oppositely reacting fluid pressure responsive surfaces and means for moving the closure member of the valve between alternate positions in response to the reaction of said surfaces to pressure differential thereacross, first and second conduit means each connected with the flowway, four-way valve means connected between said first and second conduit means and said pair of pressure responsive surfaces for movement between alternate positions connecting one surface with the first conduit means and the other surface with said second conduit means, and connecting said other surface with the first conduit means and said one surface with said second conduit means, means urging the four-way valve means to one of its alternate positions, pressure responsive means urging the said four-way valve means to its other alternate position, and means for connecting the pressure responsive means with the flowline downstream of the closure member and upstream of the restricting means, whereby reduction of pressure in said downstream portion of the flowline will cause the actuator to close the valve.

Claim 34

Apparatus of the character defined in claim 20, wherein the four-way valve means includes means connecting said conduit means with said pressure responsive surfaces, in said one alternate position of said four-way valve means, to move the closure member to flowline closing position in response to a predetermined drop in flowline pressure.

Claim 35

Apparatus of the character defined in claim 20, wherein the means urging the four-way valve means to said one position comprises spring means and means responsive to the fluid pressure of the environment surrounding the four-way valve means.

Claim 36

Apparatus of the character defined in claim 22, wherein the first and second conduit means connect with the valve flowway on opposite sides of the closure member, respectively.