Abstract: A dual cap for protecting a humidity sensor of a radiosonde of an aerological observation system includes an outer cap and an inner cap. The dual cap surrounds the humidity sensor. The outer cap has an outer ventilation hole formed in its top, and an outer air circulation opening formed in its side periphery. The side periphery of the outer cap also has a first wall that acts as a barrier to air flow. The inner cap is affixed to and is disposed inside of the outer cap. A ceiling of the inner cap faces the outer ventilation hole so as to impose a barrier to air flow. The inner cap further has an inner ventilation hole in its top and an inner air circulation opening formed in its side periphery. The inner air circulation opening faces the first wall of the outer cap.

Abstract: The disclosed embodiments include ball valves having integrated seats. The integrated seats are included in a ball body assembly of a valve body. The ball body assembly may rotate with respect to the valve body to open or close the valve. The integrated seats may contact walls of a bore to sealingly close the valve.

Abstract: An electric actuator has a motor, an electricity storing body, a switch and a resetting unit. The switch is provided in a supply path of electric power from the electricity storing body to the motor. The switch opens the supply path for electric power from the electricity storing body to the motor, in response to an instruction from an operator. The resetting unit is operated through receiving a supply of electric power from the external power supply when the external power supply has been restored from being cut off. The resetting unit closes the switch that is provided in the supply path of electric power from the electricity storing body to the motor.

Abstract: A spring seat assembly for a fluid valve includes a first spring seat having a first protruding member extending away from a first seating surface and a second spring seat having a second protruding member extending away from a second seating surface, the first spring seat being slidable relative to the second spring seat. A spring is disposed between the first seating surface and the second seating surface. A locking element is disposed on at least one of the first protruding member and the second protruding member.

Abstract: Described herein is a fluid valve assembly includes a body that defines a fluid cavity. The body includes an inlet through which fluid enters the fluid cavity and an outlet from which fluid exits the fluid cavity. The fluid valve assembly includes at least one arm rotatably coupled to the body and positioned within the fluid cavity. Additionally, the fluid valve assembly includes a flap coupled to the at least one arm. The flap includes a domed portion and a flat portion extending radially outwardly away from the domed portion.

Abstract: The invention relates to a valve assembly which includes at least one, but typically two, balls located along a passage and which balls can be moved between open and closed positions to selectively control the passage of fluid along the passage. The valve assembly includes at, at least one end thereof, a retaining assembly which allows the effective sealing against one surface of a ball and retention of the ball in position. A sealing assembly is also provided when two balls are provided, which allows effective sealing to be achieved and at least one of the two trunnions which allows each of the balls to be mounted within the valve body is located only internally of the valve body. The components of the valve assembly can in one embodiment all be inserted into and located within the valve body from one common end.

Abstract: The disclosed embodiments include ball valves having integrated seats. The integrated seats are included in a ball body assembly of a valve body. The ball body assembly may rotate with respect to the valve body to open or close the valve. The integrated seats may contact walls of a bore to sealingly close the valve.

Abstract: An electric actuator has a motor, an electricity storing body, a switch, a setting unit, a resetting unit and a setting-off unit. The switch is provided in a supply path for electric power from the electricity storing body to the motor. The switch opens and closes the supply path. The setting unit is operated through receiving a supply of electric power from the electricity storing body in response to an instruction from an operator. The setting unit opens the switch. The resetting unit is operated through r a supply of electric power from the external power supply when the external power supply has been restored from being cut off. The resetting unit closes the switch that is provided in the supply path. The setting-off unit sets off the supply of electric power from the external power supply to the resetting unit after a specific delay time has elapsed.

Abstract: An electric actuator has a switch, a setting unit and a resetting unit. The switch is provided in a supply path of electric power from an electricity storing body to a motor. The switch opens and closes the supply path. The setting unit is operated through receiving a supply of electric power from the electricity storing body in response to an instruction from an operator. The setting unit opens the switch provided in the supply path for electric power from the electricity storing body to the motor. The resetting unit is operated through receiving a supply of electric power from an external power supply when the external power supply has been restored from being cut off. The resetting unit closes the switching unit provided in the supply path of electric power from the electricity storing body to the motor.

Abstract: A multi-position rotary shear valve assembly having a metallic or ceramic stator device and a metallic or ceramic rotor device. The stator device defines a planar stator face and two or more stator channels in fluid communication with the stator face at corresponding stator ports, while the rotor device includes a substantially planar rotor face defining one or more rotor channels. A tribological coating is disposed atop at least one of the rotor and stator face. The valve assembly includes a polymer insert device defining an exposed contact face having an inner diameter less than that of the outer circumferential edge and an outer diameter more than the outer circumferential edge. The insert device is formed for press-fit insertion in a groove defined in the rotor face. The outer circumferential edge of the stator face contacts the insert exposed face during rotation between the two or more rotor positions.

Abstract: The on-off valve includes a body having a fluid path, a spherical valve body opening and closing the fluid path, a guide member opposing the valve body and having a flange portion radially extending outward, a first seat member slidable along an outer peripheral surface of the guide member and seating the valve body, an O-ring disposed between the first seat member and the guide member, a chamber formed of an inner wall portion of the fluid path, the outer peripheral surface, the flange portion, and the first seat member, and a spring member disposed in the chamber and urging the first seat member toward the valve body. In the on-off valve, a gap portion is formed between the inner wall portion and the first seat member and connects the valve body side of the fluid path to the chamber.

Abstract: A fluid flow control device includes a valve body, a bonnet, a control assembly, and a seal assembly. The valve body defines an inlet portion, an outlet portion, a bonnet opening, and a fluid flow path extending between the inlet portion and the outlet portion. The bonnet is disposed in the bonnet opening. The control assembly is at least partly supported by the bonnet, and includes a ball element disposed within the valve body and rotatable between an open position and a closed position. The valve body defines an internal recess at a location downstream from the inlet portion and adjacent the bonnet opening. The seal assembly is disposed within the internal recess and includes a movable sleeve seal, a retaining device, and one or more sealing elements for preventing leakage between the sleeve seal and the retaining device and/or the valve body.

Abstract: The disclosed embodiments include ball valves having integrated seats. The integrated seats are included in a ball body assembly of a valve body. The ball body assembly may rotate with respect to the valve body to open or close the valve. The integrated seats may contact walls of a bore to sealingly close the valve.

Abstract: Described are a rotary shear seal valve and a method for switching a high pressure fluid. The method includes applying a fixed force between a planar surface of a rotor and a planar surface of a stator. The planar surface of the rotor includes a fluidic channel and the planar surface of the stator has a pair of ports to receive and provide the fluid. A control signal is applied to a linear actuator coupled to the rotor to generate a controllable force between the planar surfaces of the rotor and stator. The control signal is responsive to a rotational state of the rotor. The total force between the planar surfaces of the rotor and the stator is substantially equal to a sum of the fixed force and the controllable force. The method reduces the wear and extends the lifetime of components in a rotary shear seal valve.

Abstract: A metal seal for valves of the ball type, the metal seal including a rigid annular body including a thickness in the longitudinal direction, and an annular lip having a front surface for relative contact with a surface of the ball, wherein said front surface for making relative contact comprises inset radial grooves.

Abstract: A multi-position valve assembly including a valve housing, a stator element and a rotor element rotatably mounted about a rotational axis. The valve assembly further includes a pressure adjustment assembly movable between a release position and a stop position, hard stopped relative to the valve housing. The pressure adjustment assembly includes a pressure adjuster device configured to movably cooperate between the rotor element and the valve housing to adjustably generate an axial compression pressure at the rotor-stator interface at a calibrated operating pressure, PC. When the pressure adjustment assembly is oriented in the release position, the axial compression pressure is substantially removed from the rotor-stator interface. In contrast, when the pressure adjustment assembly is oriented in the stop position, the axial compression pressure is substantially reproduced at the calibrated operating pressure, PC.

Abstract: A pig launching and retrieval valve, which is adapted to be mounted within a pipeline for fluid flow control and for inserting and retrieving pig devices, such as round nosed cylinders, balls, scrapers and the like, for pipeline cleaning, for separation of fluids within the pipeline and for other pipeline inspection and servicing activities. The pig valve is of universal nature, having sub flanges for adaptation of special flange mounting and/or API standard flange mounting. The pig valve has a trunnion supported valve ball and pressure energized seat members that are enabled to shift laterally within respective seat recesses and thus establish self-centering with the valve ball.

Abstract: A flow through isolation valve having a stationary member; a movable member, with a surface of the stationary member interfacing with a surface of the movable member; and at least one pin isolation valve. The pin isolation valve has a flow through internal conduit and is movable so that the internal conduit can fluidically communicate with at least one blank opening in the movable member and with a flow through internal conduit in the movable member. Movement is by rotation, linear or curvilinear translation. At least one pin isolation valve is fluidically coupled typically to a sample loop of a face seal valve, or to a pump supplying high pressure liquid to or to a column discharging liquid from a face seal valve of a high pressure liquid chromatography (HPLC) system or directly to the face seal valve.

Abstract: A metallic seal for a 90° valve features a generally rectangular shape in section that defines a chamber open to internal pressure that can enlarge the chamber to enhance the sealing effect. Sealing occurs at discrete locations at portions of the seal that are preferably rounded in shape. Overlapping ends that define the entrance to the chamber also are positioned to minimize excessive deflection and resulting plastic deformation that could close off the entrance to the chamber.

Abstract: A floating ball valve has a metal multiple component seat installed in the seat pocket. The multiple component seat further includes a support ring and at least one seal element. The support ring and the seal element are juxtaposed and both are adjacent to the ball when the floating ball valve is in a closed position. The support ring is in a overlapping complimentary position with respect to the seal element, the seal element having greater elasticity than the support ring and the support ring having a greater load bearing strength than the seal element.

Abstract: Disclosed are a method and a ball valve structure which provide for an improved seal in a trunnion mounted, double piston ball valve, which is especially useful in applications requiring a seal against high pressures, such as in the oil, gas and chemical process industries. Higher pressures on an inlet side of the valve are used, while the valve moves toward and is maintained in a valve closed position, to create movement of a ball element of the valve so as to bias the ball element against both piston seat elements (or rings) used to create the seals. This movement of the ball element thereby effectively uses such upstream pressure to create and enhance a seal between the ball element and both piston seat elements while in the valve closed position.

Abstract: Seals, ball valve assemblies, and methods of operating ball valves assemblies are provided. The seal includes an annular jacket, a restrictor, and a spring energizer. The annular jacket includes a first annular pocket and a second annular pocket. The restrictor is disposed in the first annular pocket and is capable of restricting shrinkage of the first annular pocket to a predetermined diameter range, if the seal is exposed to a temperature within a predetermined temperature range. The spring energizer is disposed in the second annular pocket and is configured to supply a force against the annular jacket to maintain the seal against a contact surface.

Abstract: Flexible seals for process control valves are disclosed. An example disclosed seal includes a seal for use with a butterfly valve. The example seal includes a substantially flexible ring-shaped carrier configured to be fixed within the butterfly valve and to surround a flow control aperture therein. Additionally, the seal includes a ring-shaped cartridge coupled to an inner diameter of the ring-shaped carrier. The cartridge includes a first portion and a second portion coupled to the first portion to define a circumferential opening to hold a seal ring.

Abstract: A flow control valve for fluidized material comprises a valve housing having a valve chamber with a valve seat and a valve plug having a flow passage, the valve plug being arranged inside the valve chamber in front of the valve seat (30) so as to be rotatable about an axis of rotation for controlling a flow through the flow control valve. It further comprises spring means biasing the valve plug against the valve seat perpendicularly to the axis of rotation, for achieving a sealing contact between the valve seat and the valve plug. According to an important aspect of the invention, the spring means comprises at least one cantilever spring (40) arranged in a clearance space opposite to the valve seat (30) so as to bias the valve plug against the valve seat.

Abstract: A high temperature ball valve seal is disclosed that achieves Class IV shutoff for operating temperatures above 550 degrees F. The ball valve seal includes a C-seal positioned between a main seal and a seal housing to prevent fluid from flowing through a secondary flowpath when the ball valve is in a closed position.

Abstract: An oil and gas collection and transmission system for petroleum, chemical industry, and so on, includes a multi-way valve with a fan-shaped flow channel sealing pair to measure production of an individual well to obtain the dynamic production data of an oil well. The multi-way valve with fan-shaped flow channel sealing pair includes a floating gating ring that is applied with contact specific pressure by an elastic component and an upper porous plane body form a gating plane sealing pair; a plurality of fan-shaped flow channel oil inlet holes are annularly and uniformly distributed on a mating surface of the upper porous plane body; the floating gating ring is configured such that it changes gradually from the upper fan-shaped flow channel to the lower round-shaped flow channel; and the inner part of the middle rotary spool is used as a public flow-guide passage.

Abstract: Seals, ball valve assemblies, and methods of operating ball valves assemblies are provided. The seal includes an annular jacket, a restrictor, and a spring energizer. The annular jacket includes a first annular pocket and a second annular pocket. The restrictor is disposed in the first annular pocket and is capable of restricting shrinkage of the first annular pocket to a predetermined diameter range, if the seal is exposed to a temperature within a predetermined temperature range. The spring energizer is disposed in the second annular pocket and is configured to supply a force against the annular jacket to maintain the seal against a contact surface.

Abstract: A selector valve (102) having at least first and second ports (108 and 110) is provided. The selector valve includes a closure element (120) selectively displaceable between a first position, wherein the closure element (120) sealingly engages the first port (108), and a second position, wherein the closure element (120) sealingly engages the second port (110). The selector valve (102) further includes a cam assembly that is configured to bias the closure element (120) into at least the first or second position in a manner such that the closure element (120) does not come into substantial contact with the first or second port (108 or 110) when being moved into the first or second position.

Abstract: A ball valve comprising a housing, a ball seat disposed within the housing, and a ball rotatably movable within the housing, and engageable with the ball seat in order to provide a seal within the ball valve and the ball seat, wherein the ball seat comprises multiple seat surfaces independently capable of engaging the ball, a first seat surface engaging the ball to form a first seal, and being arranged such that pressure acting from above pushes the first seat surface against the ball; a second seat surface being movable relative to the first seat surface and engaging the ball to form a second seal, the second seat surface being arranged such that pressure acting from below causes the second seat surface to move relative to the first seat surface and pushes the second seat surface into contact with the ball.

Abstract: A trunnion type ball valve having valve seats that are laterally moveable within seat recesses of the valve and establish sealing engagement with a valve ball member that is trunnion supported for rotational movement between open and closed positions. The valve seat members are self-centering for optimum sealing engagement with the spherical sealing surface of the ball member. The internal geometry of the seat assemblies are designed to permit optimum flow through the valve mechanism even under circumstances where the seat members are located in laterally off-center relation with respect to the centerline of the flow passages due to self-centering seat movement. The ball valve is readily adapted for fire-safe application via the use of heat resistant seals and metal-to-metal sealing of components to prevent or minimize leakage in the event of seal destruction or degradation by excess heat.

Abstract: A valve assembly is provided that includes a flowbody, a valve element movably disposed within the flowbody, and a flat beam spring-energized seal mechanism. The flat beam spring-energized seal mechanism includes a wiper seal carried by one of the flowbody and the valve element and movable between a retracted position and an extended position. The wiper seal includes a wave contour defining at least one seal wave. A flat beam spring is disposed in alignment with the at least one seal wave and configured to move the wiper seal toward the extended position when a force is exerted upon it by the at least one seal wave.

Abstract: A valve assembly comprising a housing and a valve member mounted within the housing rotatable about an axis and between at least a dispensing position and a further position, for instance a volume selection position during which a material can be withdrawn from a container, and, preferably, a seat for mounting and guiding the valve member within the housing, wherein at least one of said housing, valve member, and seat is made of a synthetic material and the assembly further comprises a spring, which urges at least two of said housing, valve member, and seat together.

Abstract: A ball valve having reduced torque requirements for rotation is presented. Torque reduction is realized by providing a shaped sealing back member to provide a back force behind essentially the entire sealing surface of the downstream seal. Torque reduction is also realized by providing a dynamic sealing configuration that varies the sealing force over the valve's operating pressure conditions. An initial bias sealing force is applied by a spring member which also provides a low uniform as-assembled valve torque. As fluid pressure increases, the sealing pressure also increases as an o-ring is forced along a ramped surface of the seal. As inlet pressure decreases, the o-ring is allowed to back down the ramped surface to reduce the sealing force against the valve member. This sealing configuration allows for reverse flow or improper installation of the ball valve, and bottoms out to maintain a sealing force at higher back pressure conditions.

Abstract: A valve seat assembly is provided for rotatable valves. The assembly has concentric rings with a spring to apply force to cause the inner ring to slide within the outer ring. There is a sliding pressure seal between the sliding surfaces. The main seal, adapted to seal against a rotating seal element, is disposed on the outer ring. A second seal, adapted to seal against the wall of the cavity in a valve body, is disposed on the inner ring. A spring may be placed in a groove in the inner or outer ring and selected to provide a force to push apart the main seal and the second seal. The diameter of the sliding seal between the rings is greater than the diameter of the second seal and the diameter of the main seal.

Abstract: A rotary valve for controlling air supply in an inflatable device comprises a first rotor (11) and the second rotor (12) driven by motor (13) with a drive pulley (14) fixed directly onto its drive spindle (15). A toothed belt (16) driven by the drive pulley (14) engages with the toothed perimeter profile of the first rotor (11), to rotate rotors (11) and (12) relative to a stator (10). As the first and/or second rotor(s) are rotated, channels and ports on the airtight interfaces between the rotors (11, 12) and the stator (10) are connected and disconnected as required by the desired inflation sequence, including all the ports sealed in one position or all the ports exhausting to atmosphere in another position. The valve can be used in conjunction with any type of inflating device, where complex porting or air routing is required, the valve achieving this in a simpler manner.

Abstract: A ball valve for refrigerating system includes a valve body, a valve seat that fits into the valve body by a screw thread, a valve ball accommodated within the valve body, two plastic sealing elements on both sides of the valve ball, a valve rod connected to the valve ball, and a valve cap on said valve rod. One of the two sealing elements is a first sealing element which is provided with a suitable spring assembly on its periphery. The spring assembly includes at least two springs with ladder-shaped longitudinal sections that are reverse-superimposed. The inside of first sealing element fits well with the surface of said valve ball, while its outside functions as a supporting surface and an acting surface for said spring assembly. The resulting configuration provides a ball valve with a desirable sealing effect.

Abstract: A rotary valve is provided with an elliptical valve disc that seats against a seal element operatively mounted in an elliptically shaped depression formed in the rigid annular portion of a seal cartridge structure carried by the valve body. Due to the elliptical shapes of the disc and corresponding seating structure, and a conical configuration of the disc periphery, sealing of the valve disc, the integrity of the seal, and the ability of the seal to completely stop the flow of fluid through the valve body are desirably improved. The centering of valve disc relative to the seal cartridge is facilitated by a specially designed disc mounting structure that eliminates any necessity of adjusting the disc along its rotational axis, and a one-piece actuator bracket is removably mounted to the valve body to substantially simplify and reduce the expense of operatively associating an actuator with the valve.

Abstract: A sleeve valve for fluid flow between a hydrocarbon reservoir and a well includes a first sleeve and a second sleeve which are relatively movable between a first position in which at least one opening in the first sleeve is aligned or misaligned with at least one opening in the second sleeve in order to admit or shut off the fluid flow. The first sleeve is provided with a radially movable sealing element that has a sealing surface adapted to rest against the second sleeve around the second sleeve opening, and at least one tension element presses the sealing element with its sealing surface against the second sleeve. A method for the assembly of such a sleeve valve includes a sealing element and a tension element placed in the outer sleeve opening and a clamping tool is adapted to the opening in the sealing element and moved outwards together with the sealing element until the sealing element is flush with the inner surface of the outer sleeve.

Abstract: A motor operated butterfly valve arrangement, at least one valve element of which is to be brought into a proper extreme position such that water leakage or the like does not occur within the pipe controlled by the valve element, without the necessity to improve dimensional or mounting accuracy of the components and without the need to lock the motor actuating the valve element. An elastically deformable elastic coupling member is provided in a coupling mechanism interconnecting the motor and the valve element. As soon as the valve element reaches the desired extreme position in contact with a stopper, the motor is rotated to deform the elastic coupling member and to improve the contact between the valve element and the stopper. The motor is stopped in the deformed state of the elastic coupling member.

Abstract: A ball valve includes a valve body and an urging member. The valve body is formed of a valve block, and two leakproof rings. The urging member is formed of a movable block, a locating element, and an elastic element located by the locating element. The movable block is provided with two slots for locating the leakproof rings, and with two annular protruded edges. In the event of deformation of the leakproof rings, the leakproof rings are pushed by the elastic element to make contact with the valve block. In the event that the leakproof rings are melted by fire, the valve block is pressed against by the annular protruded edges, so as to minimize the leakage of the ball valve.

Abstract: A ball valve includes a valve body, a cap, a disk spring, a driven member, and a spherical body. The disk spring and the driven member are disposed in the cap such that the driven member is urged by the disk spring to displace, thereby causing the driven member to push PTFE washers to come in contact with the spherical body.

Abstract: A motor operated butterfly valve arrangement, at least one valve element of which is to be brought into a proper extreme position such that water leakage or the like does not occur within the pipe controlled by the valve element, without the necessity to improve dimensional or mounting accuracy of the components and without the need to lock the motor actuating the valve element. An elastically deformable elastic coupling member is provided in a coupling mechanism interconnecting the motor and the valve element. As soon as the valve element reaches the desired extreme position in contact with a stopper, the motor is rotated to deform the elastic coupling member and to improve the contact between the valve element and the stopper. The motor is stopped in the deformed state of the elastic coupling member.

Abstract: A mix door (5) is arranged in air passages (10, 11) of an automotive air conditioning device. The mix door (5) is arranged to extend in a direction to shut an air flow blown from the upstream air passage (10) and swelled in a downstream direction with a predetermined radius of curvature. The door (5) is guided by arcuate cam grooves (19) and driven upward and downward to achieve open/close operation with the aid of a sliding mechanism (M). Compact construction, reduction in air flow resistance, smoothed handling, high sealing and high temperature controlling are achieved.

Abstract: A variable load mechanism for use in a valve seals the flow of a switched fluid. The flow passes through the mechanism in a region which includes shear seal surfaces. The lives of the components of the valve are extended by limiting the range of excursion in response to valve seat forces. The valve element is provided with a first force from a stack of Bellville washers, for example. A second force acts on the valve element through the spring and is determined by fluid pressure.

Abstract: A gas distribution box for the top burners of a stove includes a sealed gas distribution conduit in the form of a channel formed between a base plate and a cover plate. Inside the palates are elements which control the flow of gas to each burner. Only the operating shafts and a common gas inlet and individual outlets connectors protrude from the plates. The regulators for gas flow to each burner are a valve with an operating shaft and a bypass screw. The valves include two superposed flat discs, one fixed and the other rotary, fitted between the base and the cover. A pusher cooperates with the operating shaft.

Abstract: A multiple port rotary indexing vacuum valve in a liquid ink printer including a selecting member and a multiple port member. The selecting member, defines an aperture therethrough and a first axis, including a first oscillatory surface. The multiple port member defines a plurality of ports and a second axis, including a second oscillatory surface wherein the second oscillatory surface is matable with the first oscillatory surface so that relative movement therebetween aligns the aperture of the selecting member with one of the plurality of ports of the multiple port member.

Abstract: A changeover valve which accommodates thermal transients and is operable over a range of temperatures includes a crossover member (20) and a seat assembly (30) in each outlet passage (15), a thrust bearing (45) rotatably supporting the crossover member and a split load ring (40) comprising an inner ring (142) and an outer ring (146) threaded into the changeover valve body. A wave spring (150) is disposed between the inner and outer ring. The loading on the wave spring can be adjusted by the threaded in outer ring, which in turn adjusts the force of engagement of the crossover member against the seat assemblies.

Abstract: An on-off valve is provided for a rockdrill which is operable by a hydraulic fluid under pressure and which is controlled by a hydraulically biassed valve. The rockdrill is turned on and off by opening and closing the on-off valve. When the valve is turned off hydraulic pressure from an inlet line and a supply pin line to a valve line of the hydraulically biassed control valve is cut off, thereby eliminating the pressure on the supply pin. This interrupts the operating cycle of the control valve and thereby shuts off the operation of the hydraulic drill. When the on-off valve is opened the hydraulic pressure from the inlet line via the supply pin line is re-established to the valve line and to the supply pin, and the operating cycle of the control valve is re-established.

Abstract: A gasoline blending and dispensing system delivers a predetermined blend of low and high octane gasoline from low and high octane gasoline supply tanks to a nozzle for dispensing from the system. The system includes a valve responsive to valve control signals produced by a valve control for regulating the flows of the low and high octane gasolines for dispensing the predetermined blend.

Abstract: A distributor body comprises in its contact surface connection grooves which can communicate in different ways, according to the angular position of the body, with intake and outlet conduits. Rotation of the body is controlled by a motor. A stack of elastic washers acting upon a pusher ensures a suitable pressure of the contact surface against a homologous contact surface.