Hydraulic damping means for hinged check valve
AssigneeWheatley Company
InventorsRonald A. Schuller, Al D. Hogan
Life of this patent
Estimating the term…
Abstract
An improved hydraulic control means for check valves to prevent slamming of a clapper against a seat. The clapper of the check valve is connected via a crosshead to an hydraulic cylinder and a piston contained therein controls the closing of the check valve. The hydraulic cylinder has means restricting flow of fluid from below the piston in the hydraulic cylinder to above the piston in the hydraulic cylinder, but permits unrestricted flow in the opposite direction. Relief valves are included to prevent overpressurization in the hydraulic cylinder. A precharged accumulator allows for fluid expansion and contraction in the hydraulic cylinder, plus replacing fluid lost by leakage.
Claims11
A hydraulically controlled check valve for use in a high pressure pipeline, said check valve having a hinged clapper and a seat sealable against said clapper to prevent reverse flow, the improvement comprising an hydraulic control portion of the check valve which includes:
- a hydraulic cylinder having a piston slidably contained therein, said hydraulic cylinder being filled with a hydraulic fluid;
- piston rod slidably and sealably received in said hydraulic cylinder and extending through both ends thereof, said piston being connected to said piston rod in said hydraulic cylinder;
- crosshead means for connecting the first end of said piston rod to a clapper connecting rod, movement of said clapper connecting rod, said crosshead means, said piston rod and said piston being controlled by movement of the clapper to which the clapper connecting rod is attached, pressure on the first end of said piston rod being equal to pressure in the check valve;
- chamber means connected to said hydraulic cylinder for receiving a second end of said piston rod, said chamber means communicating and receiving pressure through a first valve means from the check valve;
- valve passageway means providing communication between the opposite sides of the piston for controlling the flow of hydraulic fluid from one side of the piston to the other and allowing substantially unrestricted flow in an opposite direction, said controlled flow restricting movement of said piston and said clapper to prevent slamming against the seat;
- and
- accumulator means communicating with said hydraulic cylinder, said accumulator being of a small precharged type to allow for fluid expansion and contraction and small amounts of fluid leakage.
In a check valve of the clapper type installed in a high pressure gas pipeline including a hinged clapper, the improvement comprising means to control the slamming of said clapper against its seats on reversal of flow, comprising:
- a. a chambered cylindrical hydraulic apparatus having in a central chamber a cylinder having hydraulic liquid therein, a piston slidably and sealably received in said cylinder;
- b. a first piston rod attached to said piston on a first side and sealed through a first header on a first end of said cylinder, said first piston rod extending into a first gas chamber;
- c. said first gas chamber attached at its first end to said first header and at its second end to the housing of said valve, said first gas chamber exposed to the gas pressure in said valve, slider means in said first gas chamber attached to said first piston rod;
- d. connecting rod means rotatably connected to said clapper and to said slider;
- e. second piston rod means attached to the second side of said piston and sealed through a second header on the second end of said cylinder, said second piston rod extending into a second gas chamber;
- f. said first and second piston rods having substantially equal cross sectional areas opened to the pressure in the respective gas chambers;
- g. said second gas chamber comprising a sealed chamber attached to said second header;
- h. bypass means extending between the first and second gas chambers for equalizing the pressures therein with the gas pressure in the valve;
- i. valved passageway means providing communication between the opposite sides of the piston for controlling the flow of hydraulic liquid from one side of said piston to the other and allowing substantially unrestricted liquid flow in an opposite direction;
- and
- j. accumulator means connected to said cylinder, said accumulator means being of a low precharged pressure type to allow for fluid loss around said headers and fluid expansion and contraction.
Dependencies are inferred from the claim text.