GB1601583A - Valves - Google Patents

Description

(54) IMPROVEMENTS IN AND RELATING TO VALVES (71) We, FMC CORPORATION, a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 200 E. Randolph Drive, Chicago, Illinois, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a fluid control valve, in particular for use in the hydraulic control of a subsea device and more particularly for use in hydraulic apparatus for the individual control of a relatively large number of subsea well devices using only a few hydraulic pressure source lines from a surface vessel to the seafloor.

The production of oil and gas from offshore wells has developed into a major endeavour of the petroleum industry. Wells are commonly drilled several hundred or even several thousand feet below the surface of the ocean, substantially beyond the depth at which divers can work efficiently. As a result, the drilling and operating of a subsea well must be controlled from a surface vessel or from an offshore platform. The testing, production and shutting down of the subsea well is regulated by a subsea Christmas tree which is positioned on top of the sub sea wellhead. The Christmas tree includes a plurality of valves having operators which are biased to a non-active position by spring returns, and it has been found convenient to actuate these operators by hydraulic fluid which is directly controlled from the surface vessel.For this purpose, a plurality of hydraulic lines are commonly run from the surface vessel to the wellhead to open and close these valves, and to actuate other devices in the well and the wellhead during installation, testing and operating the subsea well equipment, and also during workover procedures being performed on the well.

There is need for apparatus which can be used to control a large number of subsea operators with only a few hydraulic source lines between the surface vessel and the wellhead.

According to the present invention, there is provided a fluid control valve comprising at least two relatively movable valve members, a first said member containing a plurality of external pressure ports for connection to apparatus supplying, or responsive to, fluid pressure and a first set of internal ports disposed on the interface between said first member and a second said member, said first member further comprising at least one vent port through which fluid can be discharged from the valve to atmosphere or other low pressure and a plurality of passageways for the flow of fluid between said ports, said second said valve member contains a second set of internal ports at said interface and passageways interconnecting the internal ports of said second set, said members being relatively movable between a plurality of positions in each of which, when fluid pressure is applied to one said external port, each of the other external ports which is not in communication with said one external port is either blocked or is in communication with said vent port.

The present invention also provides a fluid control valve comprising one or more valve stator members each containing an inlet port through which fluid under pressure can enter the valve, a plurality of outlet ports, and at least one vent port through which fluid can leave the valve, and a valve rotor member containing a plurality of internal ports on the interface with the stator members and passageways through which fluid can flow between said internal ports, said valve rotor member being movable selectively between a plurality of predetermined positions in each of which at least one outlet port is in communication via the ports and passageways of the rotor member with said inlet port of the said stator member to receive fluid under pressure, the remainder of the outlet ports being in communication with said vent port through which fluid in said outlet port can be discharged or being blocked.

The invention will now be particularly described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic view, partly in elevation and partly in perspective with portions broken away, of a subsea wellhead system in which the valve of the present invention is used; Figure 2 is a schematic of the switching and valve circuitry of the apparatus described; Figures 3A and 3B comprise a table which shows the positions of the valves and switches as related to the various operations at the subsea well; Figure 4 comprises a table which illustrates the correlation between the operator which is energized, the source line used, and the position of the multiple-position valve; Figure 5 comprises a table which illustrates the correlation between the function of each subsea operator and the designation number of that operator;; Figures 6A and 6B comprise a schematic of the subsea valve; Figure 7 is an isometric view of one embodiment of the subsea valve and valve actuator; Figure 8 is an enlarged plan view of a portion of the subsea valve of Figure 7; Figure 9 is a vertical section taken along line 9-9 of Figure 8; Figure 10 comprises a schematic of the section of the valve shown in Figure 8; Figure 11 is a diagrammatic view of a portion of the valve actuator illustrating the positions of the actuator corresponding to different operating modes of the valve; Figure 12 comprises a schematic of the valve actuator; Figure 13 comprises a schematic of a modeindicator section of the subsea valve; Figure 14 is a horizontal section of the subsea valve with a portion broken away; Figure 15 is a vertical section taken along line 15-15 of Figure 14;; Figure 16 is a horizontal section taken along line 16-16 of Figure 15; Figure 17 is a horizontal section taken along line 17-17 of Figure 1S;and Figure 18 is a side elevation taken in the direction of the arrows 18-18 of Figure 14; Figures 1 and 2 diagrammatically illustrate hydraulic apparatus for controlling many valves or other sub sea wells while using only a few hydraulic pressure source lines. The apparatus is diagrammatically illustrated in Figures 1 and 2 as employed with a completion/workover riser or other type of riser 11 having its upper end connected to a control centre 1 2a on a surface vessel 12, and the riser's lower end connected to a valve container 15 that is mounted on a sub sea well Christmas tree diagrammatically illustrated at 10.Within and extending between the valve container 15 and the vessel 12 are a plurality of hydraulic pressure source lines E, F, G, H, I, J, K, L, M, N, 0 and P (not all shown) and three tubing runs 16a, 16b and 16c. The upper ends of the source lines E-P are each connected to a corresponding one of a plurality of hydraulic switches 17e, 1 7f, 1 7g, 17h, 17i, 17j, 17k, 171, 17n, 170 and 17p (not all shown), and each of the switches 17e-17p are connected to a hydraulic pump 20 which provides pressurized hydraulic fluid to the source lines when these switches are closed. The lower end of each of the source lines E-P is connected to a corresponding one of a plurality of inlet ports on a pair of multiple-position hydraulic valves 21a, 21b, each valve having a larger number of outlet ports.A plurality of outlet lines 24a-25b (Figures 2, 6a, 6b) are each connected between a corresponding one of the outlet ports of the valves 21a, 21b and one of a plurality of wellhead operators 26a-27b. These operators are used to open and close valves, connect and disconnect tree caps, control pods, etc., and provide installation, testing and operation of the well.

The schematic diagram of Figure 2 discloses hydraulic circuitry for controlling a total of twenty-eight sub sea operators using only twelve hydraulic lines between the hydraulic pump 20 (on the surface vessel) and the valves 21a, 21b (located on the seafloor). It should be noted that some of the outlet ports from the valve 21a are not used, so a few more operators could be controlled by the apparatus if these operators were needed.

The various steps of installing, testing and maintaining a typical subsea wellhead are listed in Figures 3A, 3B where these steps have been grouped together under three modes of operations or groups of steps. Figures 3A and 3B comprise a single chart in which the various operations to be performed are listed in a single column at the left of the chart while across the top of the chart (Figure 3A) are listed the various subsea operators which need to be controlled from the surface vessel. At the intersection of the rows which list the operations and the column which lists the operator is a letter (P,B,E) which indicates that hydraulic pressure or lack of hydraulic pressure is required by the operator during the operation in question.The letter P indicates that the operator requires pressure for a given operation while the letter B indicates that the operator is to be bled or a lack of pressure is required. For example, in step 2, when a subsea tree is being connected, operator 26c must be pressurized and operator 26d must be bled. Some operators may be either pressurized or beld as represented by the letter "E". Due to space limitations on the chart (Figures 3A, 3B) letters are used to represent the various operators which are identified in the function identification list of Figure 5.

For example, operator 26a is a control line to the #1 surface controlled subsea safety valve (SCSSV).

The first four steps of the operation listed in the chart (Figures 3A, 3B) include the steps for connecting the subsea tree to the well and for removing plugs from the tubing. These four steps have been labelled "mode A" (Figures 2, 4, 6A, 6B) and the valve sections 30a-30n are in the "A position" during these four steps of operation. Steps 5-12 of the operation (Figure 3A) include the steps for testing the subsea tree and the wellhead after the installation labelled "mode B" (Figures 2,4, 6A, 6B) and the valve sections 30a-30n are in the "B position" during these steps of the operation. The steps 13-27 (F (Figure 3B) include the various workover operations; these steps have been labelled "mode C" (Figures 2, 4, 6A, 6B) and the valve sections 30a-30n are in the "C position" during these steps of the operation.The various steps of the operation are controlled directly by the hydraulic switches 17c-17p (Figures 1 and 2) on the surface vessel 12. The modes A, B and C have been used as basis for designing the member ofsections and the number of positions needed in the multiple-position valves 21a, 21b.

For example, when the valves 21a, 21b (Figures 2, 6A, 6B) are in the A position the switch 17fcontrols the hydraulic power for the operator 26b. At the same time the switch 1 7g controls the hydraulic power for the operators 26c, 26j, 26k, 26m, 26n, 26p, 26q and 26s. When the valves 21a, 21b are in the B position the switch 1 7f controls the hydraulic power for the operator 26a and the switch 1 7g controls the poser for the operator 26c only. The control of the other operators at the various positions of the valves may be best seen by referring to Figure 2.The vent or bleed connections of the valve are not shown in Figure 2 in order to more clearly show the hydraulic input control circuitry; however, these vent connections may be seen in Figures 6A, 6B.

The system is preferably vented to sea with liquid from the various vents being discharged directly into the sea. In a vent-to-sea hydraulic system the hydraulic fluid contains a large percentage of water, for example, it may be 95% water. This results in a hydraulic fluid having a specific gravity of approximately 1 so that a pressure balance is achieved at the outlet of the subsea valve. The valve vents may also be connected back to the surface, but this requires at least one additional hydraulic line between the valve and a surface vessel, to return the hydraulic fluid to the hydraulic pump.

Figures 6A, 6B and 7 disclose details of a 3position, pilot-operated hydraulic valve 21 having a plurality of sections 30a-30n with each section being operable in the three different modes. These sections may be placed end-toend to form a single valve if the container 15 (Figure 1) is long enough to contain such a valve or these sections may be arranged to form two or more valves. The embodiment disclosed in Figures 1 and 2 connects the sections into a pair of valves 21a and 2 lb. The various sections 30a-30n of the valves 21a, 21b are shown in more detail in Figures 6A and 6B and with a portion of one of the valves being shown in Figure 7.Each of the valves 2 lea, 21b includes a pilot section 28 which shifts the valve from one operating position to the next operating position each time that a predetermined minimum pressure is applied to the pilot input line P.

Details of the operation of the pilot section will be discussed in connection with the physical construction of the valves as shown in Figures 7-18.

One embodiment of the valve 21 as shown in Figures 7-12 comprises a linear-slide, multiplesection flat valve having external programmable jumpers so that the configuration of the valve can readily be changed. The valve sections 30a30n are mounted on a base 33 (FIgure 7) with the larger section 30n being mounted directly on the base and each of the sections. Each of the sections includes a lower valve block 37 (Figures 7-9) which is connected to the base 33 by a plurality of machine screws 38. Each section includes a sliding jumper block 40 which is slidably connected to the lower valve block 37 by a dove-tail joint to ensure a tight, yet movable fit between the jumper block 40 and the valve block 37.

The lower valve block 37 (Figure 9) includes a plurality of passageways 41a-41n (only a portion of which are shown) which interconnect a plurality of inlet-outlet ports 44a44n with corresponging ones of a plurality of ports 45a45n at the interface of block 37 with block 40. The jumper block 40 (Figure 9) includes a plurality of vertical passageways 47a-47n, only two of which are shown, each connected between a port 48a48n at the interface of block 40 with block 37 and a corresponding one of a plurality ofjumper ports 49a-49n. An annular shear-seal ring 52 and a wave spring 53, both positioned in an annular recess 54 about each of the interface ports 45a45n, provide a fluid-tight seal between each of the vertical passageways 47a47n in the jumper block 40, and the corresponding vertical passageways 41bye in the valve block 37.

A plurality of programmable jumper lines 57a-57n (Figures 7-10) are connected between the various jumper ports 49a-49 n of the jumper block 40 to provide various combinations of connections between the outlet lines i, p, y and the source and vent lines L, V1, V2. The ends of the jumper lines 57a-57n are each provided with a tube fitting 58 which is threaded into the upper end of a corresponding one of the jumper ports 49a49n. The ends of the outlet lines i, p, y and the lines L, V1, V2 are each threaded into a corresponding one of the inlet/outlet ports 44a44n.

The jumper block 40 (Figure 8) can be moved into any one of the modes A, B or C to provide the various combinations of outlet to source and vent connections shown in Figure 10. The jumper blocks 40 are moved from one mode or position to another by an actuator section 28 (Figure 7) that includes a pair of hydraulic cylinders 58a, 58b and a pilot control section 29 having a plurality of switching valves 59a-59d (Figure 12) with each of the valves 59a-59d shown in the deenergized position.

The valves 59b, 59c switch from the deenergized position to the energized position whenever a pressure of more than 1000 psi is applied to the pilot line P, and the valves 59a, 59d switch to the energized position whenever a pressure of more than 1000 psi is applied to the pilot line P, and the valves 59a, 59d switch to the energized position whenever a pressure of more than 2000 psi is applied to the same pilot line P- The hydraulic cylinders 58a, 58b are positioned (Figure 7) at one end of the value 21 with the cylinder 58b fixed to a spacer 34a by a clevis 61 and pin 62. The cylinder 58a is supported above the spacer 34a by a pair of rods 65a, 65b (Figures 7, 11, 12).The rod 65a interconnects the cylinder 58 and a piston P2 inside the cylinder 58b, and the rod 65b interconnects the sliding jumper block 40n and a piston P1 inside the cylinder 58a. Thus, although the cylinder 58b is fixed relative to the spacer 34a and the base 33 (Figure 7), the pistons P1, P2 and the cylinder 58a are free to move along the length of the spacer 34a. A plurality of hydraulic lines 66a-66d between the pilot control section 29 and the cylinders 58a, 58b provide the hydraulic power to move the pistons P, P2. A plurality of rods or connecting links 60 rigidly interconnect the jumper blocks 40 so that each section of the switch is always in the same mode of operation.

When the hydraulic pressure from the surface vessel applied to the source line P (Figures 6A, 7, 12) is somewhat less than 1000 psi, fluid flows through the valve 59a and line 66a to the chamber of a cylinder 58a, forcing the piston P1 (Figure 12) to the right and moving fluid from the chamber b through line 66d and the valve 59d to the vent V. At the same time, fluid flows through the valve 59b and line 66b to the chamber c of the cylinder 58b, forcing the piston P2 to the right and moving fluid from the chamber d through the line 66c and the valve 59 C to the vent V.This places both pistons P1, P2 in their fully retracted position, designated mode C in Figure 11, with the jumper blocks 40 (Figures 7,8) above the right portion of each of the lower valve blocks 37, so that the mode C jumper lines 57a-57c (Figure 8) are connected between the outlet lines p, i, y, and the vent and source lines Vl , V2, L, respectively.

When the hydraulic pressure from the source line P (Figure 12) is increased to between 1000 psi and 2000 psi the valves 59b and 59c switch to their energized position wherein fluid flows through the valve 59c and line 66c to the chamber d of the cylinder 58b, thereby forcing the piston P2 to the left and fluid from the chamber c through the line 66b and valve 59b to the vent V. As the piston P2 moves to the left, the rod 65a (Figures 7, 11) is extended from the cylinder 58b, thereby moving the cylinder 58a to the left and the jumper blocks 40 into the mode B as shown in Figures 8, 10, 11.

When the hydraulic pressure from the source line P (Figure 12) is increased to above 2000 psi the valves 59a, 59d are also switched to their energized position wherein fluid flows through the valve 59d and line 66d to the chamber b of the cylinder 58a, forcing the piston P1 to the left and moving fluid from the chamber a through the line 66a and the valve 59a to the vent V. This extends both the rods 65a, 65b, and moves the jumper blocks 40 into the mode A (Figures 8, 10, 11). Thus, the mode of operation of the linear-slide valve can be controlled from a remote position by applying different hydraulic pressures to the pilot valve 29.

Another embodiment of the invention is shown in Figures 13-18 that illustrate a rotary type valve 70 with internal passageways instead of the external jumpers of the first embodiment illustrated in Figures 7-12. These internal passageways can be drilled or otherwise formed to provide the same passageway system provided by the external jumpers, so that the ultimate function of both valves is the same.

The valve 70 comprises a plurality of sections 30a-30n (Figure 18) each having a cylindrical outer housing 67 with a flange 67a (Figures 14, 15) at one end thereof, and a wall 68 that encloses the other end thereof. The wall 68 includes a central bore 68a having an annular shaft 69 rotatably mounted therein. The secttions are each bolted to at least one adjacent section by a plurality of bolts 72 (Figures 14, 16-18) extending through bores 73 in the flanges 67a.

Each section (Figures 14, 15) includes an annular rotor 75 mounted between the wall 68 and a cap 76 which is threaded to the upper end of the housing 67. The shaft 69 is rotatably mounted through an annular bore 92 in the center of the cap 76, and the shaft is secured to the rotor 75 (Figure 14) by a key 83. A thrust bearing 77 (Figure 15), positioned in an annular groove 79 in the bottom of the cap 76, provides a bearing surface which rests against the top surface of the rotor 75 to limit upward movement of the rotor. The wall 68 (Figure 15) includes a plurality of passageways 80a-80n which interconnect a plurality of inlet/outlet ports 81a-81n (Figures 14, 15) with corresponding ones of a plurality of interface ports 82a-82n (Figure 15).An annular shear-seal ring 52 and a wave spring 53,both positioned in an annular recess 85 about each of the interface ports 82a-82n, provide a fluid-tight seal between each of the vertical passageways 86-a-86n in the wall 68, and the corresponding vertical passageways 87a-87n in the rotor 75.

A plurality of horizontal passageways 90a90n (Figures 14-16) interconnect the various vertical passageways 87a-87n in the rotor 75 and connect other vertical passageways 87a87n with a chamber 91, between the outer housing 67 and the rotor 75. This chamber 91 is vented to the sea by a vent V (Figure 14) so that only a single vent is needed instead of the pair of vents employed in the embodiment of Figures 7-12. A pair of annular seals 95 (Figure 15) mounted around the shaft 69, and an annular seal 96 mounted between the housing 67 and the cap 76, prevent leakage of fluid from the chamber 91.

The upper end of the shaft 69 (Figure 18) is attached to a mechanism 98 which rotates the multiple-position valve 70 into the positions or modes A, B, C. The mechanism 98 includes a lower ratchet section 99 having a plurality of teeth 99a, and an upper ratchet section 100.

The upper ratchet section 100 is biased against the lower ratchet section 99 by a spring 103 which is wound about a shaft 104. The shaft 104 is connected between the upper ratchet section 100 and a spur gear 107 which is connected to a movable rack 108. The rack 108 is connected to a piston 109 by a rod 112 which is mounted inside a cylinder 113. The piston is biased toward the left end of the cylinder 113 by a spring 114.

Each time the hydraulic cylinder 113 is energized by hydraulic fluid from the pilot input line P, the rack 108 moves toward the right (Figure 18) thereby causing the spur gear 107, the ratchet sections 100, 99, the shaft 69 and each ofthe rotors 75 (Figure 15) to rotate 120 degrees in a clockwise direction (as viewed from above) with the vertical passageways 871-37n in the rotors stopping at a position adjacent the vertical passageways 86a-86n in the wall 68 (Figure 15). When the hydraulic cylinder 113 (Figure 18) is deenergized the spring 114 causes the piston 109, the rod 112 and the rack 108 to move to the left and causing the upper ratchet section 100 to rotate counter-clockwise.However, the lower ratchet section remains stationary due to the friction between the seals 95 (Figure 15) and the shaft 69 and due to the shape of the teeth on the ratchet sections 99 and 100 which permit the upper ratchet section 100 to rotate counterclockwise while the lower ratchet section 99 remains in a fixed position. Each 120 degree rotation of the shaft 69 causes the valve to change from mode A to mode B, or from mode B to mode C, or from mode C to mode A.

The various connections between the inlet ports and the outlet ports can be seen in Figures 2, 6a and 6b. For example, when the valve is in mode A, in section 30b of the valve the inlet line F is connected to the outlet line 24b and to the operator 26b. When the valve is moved into mode B, the inlet line F is connectedto the outlet line 24a and to the operator 26a. The section 30n (Figures 2, 6b) of the valve connects all of the operators 26j, 26k, 26m, 26n, 26p, 26q and 26s in parallel when the valve is in mode A so that power to these operators is all controlled by the switch 17g. In the B and C modes of the valve, each of these operators is controlled by an individual one of the switches 17j-17p.It may be noted that the "B" and "C" portions of the 30n section of the valve are identical, but both portions are needed as all of the sections of the valve change from mode B to mode C when the pilot valve causes the rotors 75 (Figure 16) to rotate from position B to position C.

The details of the connections for one of the sections of the rotary switch can be seen in Figures 10, 14, 16 and 17. As shown in the mode A, the inlet line K is connected to the outlet line i by the horizontal passageways 80c, 90h, 80b (Figure 14) and the vertical passageways 86c, 86h (Figure 17) 87h, 87c (Figure 16).

The inlet/outlet line p is connected to the vent V by the horizontal passageways 80a (Figures 14, 15, 17), 90a (Figures 14-16), the vertical passageways 86a (Figures 15, 17) 87a (Figures 15, 16) and the chamber 91 (Figures 14-16). In the mode B, the rotor 75 (Figure 16) is moved 120 degrees clockwise from the position shown in Figure 16 so that the inlet line K is connected to the inlet/outlet line p by the hor izontal passageways 80a, 80c (Figure 17), 90c (Figures 15-16) and the vertical passageways 86a, 86c (Figure 17), 87e, 87d (Figures 15-16).

A mode-indicator section 117 of the rotary switch 21 as disclosed in Figure 13 provides means for remotely checking the position or mode in which the switch of Figures 14-18 is operating. The mode-indicator section 117 includes a plurality of pressure-relief valves 11 8a- 11 8c and a valve section 3 0y (Figure 13) which is preferably connected to the lower end of the shaft 69 (Figure 18) although the section 30y could be connected anywhwere along the length of the shaft. Each of the pressure-relief valves (Figure 13) prevents the pressure drop across the valve from exceeding the value shown in the Figure 13. For example, the maximum pressure drop between the inlet port 119a and the vent port V of the valve 118a is 1500 psi.

Each of the pressure-relief valves 118a-118c is connected to the source line P in a corresponding one of the modes A, B, C and prevents the pressure in the source line P from raising above the pressure drop across the relief valve.

A pressure gauge (not shown) mounted on the surface vessel 12 (Figure 1) and connected to the line P is used to indicate the pressure on the line P and thereby indicate the mode of operation of the rotary switch 21. When the pressure in the source line P increases about 750 psi, the piston 109 (Figures 13, 18) moves the rack 108, spur gear 107 and the shaft 69 a total of 120 degrees so that the rotary switch moves into one of the modes A, B or C and connects one of the pressure-relief valves to the source line P. For example, in mode B (Figure 13) the pressure-relief valve 1 18b is connected to the source line P through the valve section 30y so that the pressure in the source line P cannot increase above 2000 psi.In mode A the pressure-relief valve 11 8a is connected to the line P so that the pressure in the source line P cannot increase above 1500 psi and in mode C the valve 1 18c is connected to the line P and the pressure in the line P cannot increase above 2500 psi.

The apparatus described provides a means for controlling the operation of a relatively large number of hydraulic control lines between a much smaller number of hydraulic control lines between a surface vessel or a surface platform and a multiple-position subsea valve which is positioned near the sub sea operators. The multiple-position valve has a plurality ofsections with each section having an input port, a vent port and a plurality of output ports. Connected between each of the input ports and a source of hydraulic power on the surface vessel is a source line having a hydraulic switch connected therein.

A separate subsea operator may be individually controlled by a corresponding one of the hydraulic switches at each position of the subsea valve.

Features of the apparatus and method described above form the subject of our copending patent applications nos. 8216/77 and 23272/78 serial no's 1 601 581 and 1 601 582.

WHAT WE CLAIM IS: 1. A fluid control valve comprising at least two relatively movable valve members, a first said member containing a plurality of external pressure ports for connection to apparatus supplying, or responsive to, fluid pressure and a first set of internal ports disposed on the interface between said first member and a second said member, said first member further comprising at least one vent port through which fluid can be discharged from the valve to atmosphere or other low pressure and a plurality of passageways for the flow of fluid between said ports, said second said valve member contains a second set of internal ports at said interface and passageways interconnecting the internal ports of said second set, said members being relatively movable between a plurality of positions in each of which, when fluid pressure is applied to one said extemal port, each of the other external ports which is not in communication with said one external port is either blocked or is in communication with said vent port.

2. A valve according to Claim 1 wherein the passageways of the second member include ducting which is movable relatively to the second member to selectively interconnect the internal ports of said second set.

3. A valve according to Claim 2 wherein the second valve member is rotatable to vary the intercommunication bctween the internal ports of said two sets.

4. A fluid control valve comprising one or more valve stator members each containing an inlet port through which fluid under pressure can enter the valve, a plurality of outlet ports, and at least one vant port through which fluid can leave the valve, and a valve rotor member containing a plurality of internal ports on the interface with the stator members and passageways through which fluid can flow between said internal ports, said valve rotor member being movable selectively between a plurality of predetermined positions in each of which at least one outlet port is in communication via the ports and passageways of the rotor member with said inlet port of the said stator member to receive fluid under pressure, the remainder of the outlet ports being in communication with said vent port through which fluid in said outlet port can be discharged, or being blocked.

5. A valve according to Claim 4 wherein the valve rotor member is rotatable within a casing formed at least in part by said one or more valve stator members, the valve rotor member having first and second opposite axially-facing surfaces and a cylindrical peripheral surface, at least one of said axially-facing surfaces containing a first set of said internal ports which communicate via said passageways with a second set of internal ports in one or more surfaces of the rotor member, or with at least one further port, said further port communicating with a space surrounding the rotor member which in turn communicates with said vent port, and said casing having a third set of ports which communicate with said inlet port and outlet ports, the arrangement being such that in each position of the rotor member, each port of said third set is in fluid-sealed communication with a port of said first or second set or is in flowblocking contact with a said axially-facing surface of the rotary member.

6. A valve according to Claim 5 wherein each port of said second set is contained in the axially-facing surface of the rotor member which contains the port of said first set, and the or each said further port is contained in said peripheral surface of the rotor member.

7. A valve assembly comprising a plurality of valves each valve being in accordance with any one of the preceding claims and wherein the movable members of the valves are interconnected for movement in unison.

8. A well head control system containing a valve, according to any one of Claims 1 to 6 or a valve assembly according to Claim 7, and a plurality of hydraulic operators connected to outlet ports of said valve or valve assembly.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. lines between a surface vessel or a surface platform and a multiple-position subsea valve which is positioned near the sub sea operators. The multiple-position valve has a plurality ofsections with each section having an input port, a vent port and a plurality of output ports. Connected between each of the input ports and a source of hydraulic power on the surface vessel is a source line having a hydraulic switch connected therein. A separate subsea operator may be individually controlled by a corresponding one of the hydraulic switches at each position of the subsea valve. Features of the apparatus and method described above form the subject of our copending patent applications nos. 8216/77 and 23272/78 serial no's 1 601 581 and 1 601 582. WHAT WE CLAIM IS:

1. A fluid control valve comprising at least two relatively movable valve members, a first said member containing a plurality of external pressure ports for connection to apparatus supplying, or responsive to, fluid pressure and a first set of internal ports disposed on the interface between said first member and a second said member, said first member further comprising at least one vent port through which fluid can be discharged from the valve to atmosphere or other low pressure and a plurality of passageways for the flow of fluid between said ports, said second said valve member contains a second set of internal ports at said interface and passageways interconnecting the internal ports of said second set, said members being relatively movable between a plurality of positions in each of which, when fluid pressure is applied to one said extemal port, each of the other external ports which is not in communication with said one external port is either blocked or is in communication with said vent port.

2. A valve according to Claim 1 wherein the passageways of the second member include ducting which is movable relatively to the second member to selectively interconnect the internal ports of said second set.

3. A valve according to Claim 2 wherein the second valve member is rotatable to vary the intercommunication bctween the internal ports of said two sets.

4. A fluid control valve comprising one or more valve stator members each containing an inlet port through which fluid under pressure can enter the valve, a plurality of outlet ports, and at least one vant port through which fluid can leave the valve, and a valve rotor member containing a plurality of internal ports on the interface with the stator members and passageways through which fluid can flow between said internal ports, said valve rotor member being movable selectively between a plurality of predetermined positions in each of which at least one outlet port is in communication via the ports and passageways of the rotor member with said inlet port of the said stator member to receive fluid under pressure, the remainder of the outlet ports being in communication with said vent port through which fluid in said outlet port can be discharged, or being blocked.

5. A valve according to Claim 4 wherein the valve rotor member is rotatable within a casing formed at least in part by said one or more valve stator members, the valve rotor member having first and second opposite axially-facing surfaces and a cylindrical peripheral surface, at least one of said axially-facing surfaces containing a first set of said internal ports which communicate via said passageways with a second set of internal ports in one or more surfaces of the rotor member, or with at least one further port, said further port communicating with a space surrounding the rotor member which in turn communicates with said vent port, and said casing having a third set of ports which communicate with said inlet port and outlet ports, the arrangement being such that in each position of the rotor member, each port of said third set is in fluid-sealed communication with a port of said first or second set or is in flowblocking contact with a said axially-facing surface of the rotary member.

6. A valve according to Claim 5 wherein each port of said second set is contained in the axially-facing surface of the rotor member which contains the port of said first set, and the or each said further port is contained in said peripheral surface of the rotor member.

7. A valve assembly comprising a plurality of valves each valve being in accordance with any one of the preceding claims and wherein the movable members of the valves are interconnected for movement in unison.

8. A well head control system containing a valve, according to any one of Claims 1 to 6 or a valve assembly according to Claim 7, and a plurality of hydraulic operators connected to outlet ports of said valve or valve assembly.