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A block valve (10) for selectively establishing and selectively blocking communication between a pressurized fluid supply (30), a fluid actuated device (DHSV) and a reservoir (35). The valve comprises a valve body (41, 42) with an inlet (81), an outlet (82) and a bleed port (83) and first and second

A block valve (10) for selectively establishing and selectively blocking communication between a pressurized fluid supply (30), a fluid actuated device (DHSV) and a reservoir (35). The valve comprises a valve body (41, 42) with an inlet (81), an outlet (82) and a bleed port (83) and first and second piston-type plunger elements (61, 71) slidably mounted in piston chambers (51, 52) formed in the bore (43, 45) of the valve body. The second plunger element (71) is slidably mounted on the first plunger element (61) in sleeved relation therewith. Both plunger elements (61, 71) are continuously urged by springs (66, 75), respectively, to a first operating position wherein communication between the ports (81, 82, 83) is blocked by seal means (94, 95, 96) and blocking means (64) mounted on the plunger elements. Ports (49, 56) in the valve body are connected to a pilot pressure supply (12) whereby the plunger elements (61, 71) are simultaneously movable to second operating positions upon application of pilot pressure to the plunger elements. An annular chamber (91) formed by a reduction in diameter of the second plunger element is placed in communication between the inlet and outlet ports (81, 82) to establish communication therebetween and the seal means (94, 95, 96) are disposed so that communication is blocked between each of these ports and the bleed port (83). Upon interruption of the pilot supply (12), the pressurized pilot fluid is removed from the plunger elements but is removed from the plunger element (61) through a fluid delay circuit (98, 99) whereby the second plunger element (71) is returnable to its first operating position before the first plunger element (61) reaches its first operating position thus blocking communication between the inlet and outlet ports (81, 82) while opening communication between the outlet port (82) and bleed port (83) for a limited period. When the valve (10) is connected in a safety system to control the flow line (84) to a fluid actuator for a DHSV, the valve will respond to a shut-down signal from the safety system to permit the downhole actuator to completely bleed its pressure and allow the DHSV to completely close in this limited time period prior to establishing a positive block in the control line between the DHSV and the safety system.

대표청구항 ▼

A valve device adapted for controlling distribution of fluid between a hydraulic fluid supply, a fluid actuator device and a reservoir, said device comprising: an elongate valve body having an axial bore extending therethrough including a reduced diameter bore section and an enlargement thereof whic

A valve device adapted for controlling distribution of fluid between a hydraulic fluid supply, a fluid actuator device and a reservoir, said device comprising: an elongate valve body having an axial bore extending therethrough including a reduced diameter bore section and an enlargement thereof which provides an enlarged diameter bore section; transverse wall means dividing said enlarged diameter bore section into longitudinally spaced first and second piston chambers, said valve body being provided with an inlet port, an outlet port and a bleed port which communicate with the reduced diameter section of the axial bore at longitudinally spaced locations; a first plunger element slidably mounted in said axial bore for movement between first and second operating positions, said first plunger element including an elongate rod having an enlarged diameter blocking portion slidably disposed within the reduced diameter bore section and a first piston affixed to said rod and disposed within said first piston chamber; a second plunger element comprising an elongate rod having a reduced external diameter portion cooperating with the wall of said axial bore to define an annular chamber therewith, a second piston affixed to the rod of the second plunger element and an elongate bore extending axially through the rod and piston portions of said second plunger element, said second plunger element being disposed intermediate the first piston and the blocking portion of the rod of the first plunger element in sleeved relationship to the rod portion of the first plunger element, said second plunger element being adapted for sliding movement on the rod portion of the first plunger element between first and second operating positions; first spring means for urging the first plunger element and said first piston towards its first operating position; second spring means for urging the second plunger element and said second piston in a direction outwardly of said reduced diameter bore section towards its first operating position, said first and second piston chambers being each provided with fluid inlet port means whereby a pressurized pilot fluid delivered to said piston chambers through said fluid inlet port means will simultaneously urge the first and second plunger elements to their respective second operating positions, each said plunger element being moved by its associated spring means to the first operating position when pressurized pilot fluid is removed from the piston chambers, said enlarged diameter blocking portion of the first plunger element being positioned intermediate the inlet and bleed ports of the valve body and adjacent said outlet port when the first plunger element is in its first operating position to block fluid communication between the respective inlet, outlet and bleed ports of the valve body; first seal means mounted about the periphery of the rod of the second plunger element at a location intermediate the second piston and said annular chamber for blocking fluid communication between said inlet port and the second piston chamber for all operating positions of the second plunger element; and second seal means mounted about the periphery of the rod portion of the second plunger element and located intermediate the blocking portion of the first plunger element and said annular chamber, said second seal means being disposed intermediate the inlet and outlet ports when the second plunger element is in its first operating position for blocking fluid communication between the inlet port and the outlet port of the valve, said second seal means being disposed intermediate the outlet port and the bleed port when said second plunger element is in the second operating position for blocking communication therebetween and said annular chamber being disposed adjacent both said inlet and outlet ports in the second operating position of the second plunger element for establishing communication between the inlet and outlet ports when the second plunger element is in its second operating position, said blocking portion and seal means being simultaneously carried with said plunger elements on moving to said second operating position.