Abstract: A flow control and pressure reducing valve has a valve body with an inlet chamber and outlet chamber separated by a partition plate. A plurality of passages are formed in the valve body spaced circumferentially around the partition plate and have an inlet portion opening into the inlet chamber and an outlet portion opening into the outlet chamber. Elastomeric flow control means are positioned in the passages and are responsive to pressurized fluid introduced therein to control flow of fluid through the passages around the partition plate. The valve configuration allows the mounting of inlet and outlet gates within the inlet and outlet chambers to eliminate the need for separate gate valves. An auxiliary flow passage may be provided through the partition plate and flow controlled therethrough to increase the flow capacity of the valve jet still provide full flow and pressure control. Air inlet and relief valves may also be provided as an integral part of the valve.

Abstract: A low pressure drop valve connectible to a source of pressurized hydraulic fluid for modulating hydraulic fluid flow is provided; it includes a valve body defining an axially extending tapered bore and having hydraulic flow inlet and outlet ports, a plug valve movable axially in that bore and having an externally tapered surface facing the tapered bore and movable axially relative thereto to increase or decrease a gap formed between the tapered surface and the tapered bore, for controlling the flow of hydraulic fluid via the gap and at least one of said ports, and apparatus responsive to a side stream of pressurized hydraulic fluid to control axial movement of the plug valve in the tapered bore, including first and second pistons connected with the plug valve to move axially therewith, the valve body forming first and second cylinders respectively receiving the pistons for application of hydraulic fluid pressure to the pistons for displacing the pistons and plug valve axially, and protective O-rings in the cy

Abstract: A drain valve for a compressed air tank is pneumatically activated by the residual air which is released from an air compressor when the air compressor comes to a stop after an active cycle. The invention allows for consistent and reliable draining of condensation from a compressed air tank. The energy of the residual air released is used to operate the valve. Under favorable conditions, the valve is operated at a frequency proportional to the rate of moisture condensation.

Abstract: A latching trip valve for opening and closing a safety device. The trip valve is operable manually and from the pressure of a pilot circuit which monitors the operating conditions of a pipeline. A floating seat is movable under the influence of a longitudinal movable poppet and its included seal means. The floating seat and seal means forms a closed passage until the pressure of the pilot circuit decreases whereas the passage is opened.

Abstract: A paint discharge control device includes a housing having a paint supply port and a paint discharge port defined therein, a paint passage through which the paint supply and discharge ports communicate with each other, a diaphragm disposed in the paint passage and actuatable by air under pressure for controlling the rate of a paint flow through said paint passage, a piston slidably disposed in the housing and having a hole defined therein as part of the paint passage, and a needle valve supported in the housing and having a portion disposed in the hole in the piston. The paint passage includes a paint discharge control passageway defined between the hole and the needle valve portion. The cross-sectional area of the paint discharge control passageway can be varied in response to sliding movement of the piston in the housing.

Abstract: A set point pressure control circuit is disclosed for controlling pressure in a high pressure environment. The circuit includes a high pressure communicating, low pressure actuated valve. The valve includes a housing in which a valve member is disposed. The valve member has an axial passageway defined therethrough for communicating a high pressure port across a piston of the valve member to an opposite high pressure chamber which is placed in communication with a low pressure port when the valve member is in an open position.

Abstract: The bleeder comprises a hydraulically remotely controlled bleed valve (150) and device for guaranteeing that during bleeding, the gas is exhausted away from the well head zone. The bleed valve (150) is advantageously situated at the top end of the pressure lock and has a valve body (9) defining a main channel (17) of sufficient cross-section to pass to wireline tool. The bleed valve also has a gas exhaust lateral orifice (16) for being put selectively into communication with a first transverse channel (15) which opens out into the main channel (17) by a closure member constituted by a valve seat and a valve member formed at one end of a piston (5). A second transverse channel (14) puts the main channel (17) into communication with a rear face of the piston (5), where the rear face has a greater section than its valve-forming front face.

Abstract: A removable insert valve provided with a piston which can be displaced in a bore in a valve housing by pressure fluid action, there being formed at one end of the bore a valve seat and a pressure fluid passage leading through the housing traversely to the bore. The piston is free of O-rings and is provided with first a ledge to constitute a pressure area in the region of the opening of the transverse passage into the bore in combination with a control pressure pump to selectively apply opening and closing pressure to a second ledge on the piston, in order to achieve more rapid operation of the valve.

Abstract: A metering valve adapted to operate a seat on a side of an actuator port by means of a poppet section of a main poppet arranged in a valve casing to selectively communicate the actuator port to a tank passage. The main poppet is formed with a pressure chamber on a side thereof opposite to the poppet section. The pressure chamber has a pressure receiving area substantially equal to that of the seat. Also, the main poppet is formed with a through-hole constantly communicated to the actuator port and a pilot chamber to which pilot pressure for moving the main poppet in a direction of opening the seat is applied. Thus, the metering valve is capable of stably accomplishing its control irrespective of a variation of pressure on the side of the actuator port.

Abstract: A two-way control valve includes a valve member with a longitudinal bore connecting its opposite ends with each other. A housing receives the movable valve member and has two attachment ports. A control piston is operatively coupled with the valve member. To provide a two-way valve permitting pressure medium to flow in both directions when the valve member is moved from its closed position, the control piston is tightly or fixedly connected with the valve member and is arranged as an annular collar on the periphery of the valve member. The longitudinal bore is free of constrictions.

Abstract: A hydraulic pilot operated directional control valve (30; 60; 70) in which at least one pilot hydraulic pressure chamber (40, 41; 76) is formed within a block (39; 64; 75) of a hydraulic pilot operating section (32, 33; 61; 72), and pilot hydraulic fluid is led into the pilot hydraulic pressure chamber to drive a spool (37, 38; 74). A drain passageway (54; 82) is provided in the vicinity of the pilot hydraulic pressure chamber (40, 41; 76) within the block (39; 64; 75), and the pilot hydraulic pressure chamber and the drain passageway communicate with each other through minute passageway means (52, 53; 83) for bleeding air.

Abstract: A high pressure fluid valve includes a tubular portion with a valve seat on its end and a closure element for engaging the valve seat. A piston carries either the tubular portion or the closure element as a movable valve member, with the other being fixed. A first fluid chamber is provided adjacent the valve seat and a second fluid chamber is spaced therefrom adjacent the other end of the movable valve member. When the movable valve member is actuated, one of the fluid chambers increases in volume by the same amount that the other decreases in volume, thereby maintaining the internal volume of the valve constant.

Abstract: Fuel is directed to the stages of an afterburner by metering flow to the stages with a single metering valve and by controlling the flow to each stage by means of an integral shutoff and regulating valve. Each shutoff valve opens and closes the fuel flow to a stage as required. Each regulating valve, which is housed within a respective shutoff valve, regulates flow to each segment as a function of the pressure drop across the metering valve so that a constant weight flow to the segment is achieved.

Abstract: A vacuum controller for controlling the vacuum at a controlled vacuum which includes a balanced piston arrangement coupled to a valve piston reciprocal with respet to a valve seat positioned between the controlled vacuum and a high header or source vacuum. A throttling of the header vacuum takes place across the space between the valve piston and valve seat and is such that the header vacuum does not influence the movement of the valve piston.

Abstract: A gate valve (10) having a valve operator (40) fully contained within a valve body with means for communicating fluid under pressure to the valve operator (40) to move a gate (32) to a valve open or a valve closed position. The valve operator (40) is located within the gate chamber (30) and the gate (32) itself contains and forms part of the valve operator (40) and, thus, considerable space is conserved. In one embodiment, the means for communicating pressure fluid to the valve operator includes a manifold (16) to allow the valve body (12) to rotate as part of a drilling assembly yet be remotely controllable. In another embodiment, the manifold may be eliminated for the use of the valve does not require rotation.This invention introduces gate valve technology into drilling operations to displace ball valves as kelly cock valves.

Abstract: An air cannon which includes a pressure tank with an inlet opening and an outlet opening for air, whereby the outlet opening is composed of a tube which is airtightly fastened in the wall of the pressure tank and the one open end terminates inside the pressure tank and the other open end extends out of the pressure tank. A cylindrical shaped second tube is fixed in the pressure tank with an open end and a closed end, generally concentric to the mentioned first tube, of which the cross section is larger than the cross section of the first tube. The first tube extends through the open end into the inside of the second tube, and is generally concentric to it. In the bottom of the second tube there is provided an in and outlet opening for the in and outflow of air.

Abstract: Apparatus for sending pressure pulses through drilling fluid in a drill string in a well bore includes an assembly adapted to be lowered from the surface through the drill string to a position adjacent the lower end of the drill string. The external dimension of the assembly is substantially less than that of the internal diameter of the drill string, so there is always a substantial clearance between the assembly exterior and the drill string interior to permit a substantial flow of drilling fluid down the drill string, past the assembly, through a drill bit, and into an annular space between the drill string exterior and the well bore. The assembly includes an internal bore to permit drilling fluid to flow through the assembly. Means are provided for intermittently restricting flow of drilling fluid through the assembly bore to send the pressure pulses to the surface in response to the magnitude of a downhole condition to be measured.

Abstract: The control valve for the re-setting of the props at a predetermined minimum setting pressure is connected at respective junctions to a high pressure conduit, to the pressure chambers of the props, to the prop-setting conduit and to the return-flow conduit leading to the annular chambers of the props. The spring-loaded closure body is guided displaceably in the valve housing by journals on each of the two sides of the valve cone. The ends of the journals are formed as actuation faces. The valve cone seals off the high pressure junction and the junctions leading to the pressure chambers of the prop and opens only when a predetermined minimum setting pressure at the junction is exceeded. For closure, the control valve is loaded through the junction on the actuation area of the journal with the pressure fluid conducted to the annular chambers of the props.

Abstract: Process for the control of turbidity currents, especially of high temperature lubricants in the form of graphite and polymers, suspended in water, with a viscosity of 1,000 to 20,000 cP at a temperature of up to 250 bars and a current velocity of up to 120 m/sec. Closing and opening times of 2 to 20 milliseconds are maintained. Apparatus for achieving the process, which is a switching-off valve having closing and opening times of 2 to 20 milliseconds. The switching-off valve preferably is a plunger valve.

Abstract: An adjustable throttle valve is controlled by a low pressure control pressure acting on a spring urged adjusting cylinder for positioning the end of a follow-up piston adjacent the end of a discharge channel extending the length of a throttle piston; power fluid flows from a source through a discharge opening between a housing and the throttle piston with the spring force, the control pressure, infeed pressure and discharge pressure acting in concert to maintain the end of the follow-up piston adjacent but slightly spaced from the end of the discharge channel for maintaining throttle piston equilibrium.

Abstract: Apparatus useful on space vehicles as a valve for establishing external pressure in a pressure container or otherwise as an engine for performing work. The apparatus is responsive to atomspheric pressure retained in a plenum are applied to one side of a piston which atomspheric pressure is greater than an external pressure applied to the other side of the piston in a vacuum environment. A method for operation of such apparatus is also disclosed.

Abstract: A blowout protector for use between sections of well tubing at a well head comprises a flat rectangular housing having top and bottom plates with aligned openings connected to the respective tubing sections, the housing defining an internal chamber. A closure plate is movable piston-wise within the chamber between respective terminal positions at opposite ends of the chamber. The closure plate has an opening therein which aligns with the respective openings in the top and bottom plates when the closure plate is in one terminal position in order to allow well fluid to flow through the protector. In the other terminal position the closure plate forms a barrier to fluid flow through the housing. Fluid pressure inlet and exhaust ports are provided at opposite ends of the housing for moving the closure plate between its respective positions.

Abstract: The valve has a cylindrical, cartridge-like housing in which a piston is slidably disposed. The piston subdivides the housing into an outer chamber, at one housing end, into which oil under pressure is admitted, and an inner chamber from which oil is discharged. Ports formed in the housing open onto the inner chamber and allow the oil to pass therethrough and on into an associated air compressor. The other end of the valve housing defines a control chamber. The piston has a depending, cylindrical shank which (a) moves into, and removes from, the control chamber, and (b) has a disc, fixed onto the end of the shank, which is sealingly engaged with the wall of the control chamber. Channels are formed in the periphery of the piston, to allow oil to flow from the outer chamber to the inner chamber, but a land in the housing defines a seat for the piston which, when the piston closes thereupon, interdicts the aforesaid oil flow.

Abstract: A gas pressure actuator for effecting the reciprocation of the stem of a valve subject to high-pressure loading comprises a tubular housing secured to the valve bonnet and defining a main cylinder chamber connected in axially series relationship with an auxiliary piston chamber which, in turn, communicates with a secondary fluid pressure chamber containing a compressible spring. A rod-like actuator is slidably and sealably mounted within the actuator housing and carries a main piston which cooperates with the main cylinder chamber in sliding and sealable relationship. The auxiliary piston chamber slidably and sealably mounts an auxiliary piston which is movable independently of the main piston. The actuating movement of the main piston produced by the introduction of gas pressure into the main cylinder produces an axial movement of the actuating rod and a compression of the spring. The spring-containing secondary chamber defined by the actuator housing is filled with a virtually non-compressible fluid.

Abstract: A suck-back pump for preventing any additional amount of liquid from dropping out of the tip of a delivery pipe, after a predetermined amount of liquid has been delivered from the delivery pipe. The suck-back pump includes inlet and outlet ports for liquid, first and second chamber respectively connected with the inlet and outlet ports, a communicating passage for connecting the first and second chambers with each other, a shut-off valve movable to close the communicating passage, and a suction element movable to change the volume of the second chamber. The actuation of the suction element is retarded so that it is actuated after the shut-off valve has been actuated.

Abstract: A control system (10) employable for purposes of effecting the operation of a plurality of actuable devices, which are located at a subsea site, from a position that is remote therefrom. More specifically, the subject control system (10) is particularly suited for employment for purposes of hydraulically effecting the operation of the valves of a subsea christmas tree (30). To this end, the subject control system (10), on the one hand, is connected in fluid flow relation with a surface control center (16) from which hydraulic fluid is supplied under pressure, and, on the other hand, is connected to a subsea sequence valving means (12) which receives the hydraulic fluid under pressure from the surface control center (16) and in turn transmits hydraulic power to the operators (46, 48, 50, 52, 54, 56) of the christmas tree valves to cause the latter to move in accordance with a predetermined operating program (32).

Abstract: A mixing head suitable for mixing two or more liquids is provided. During the mixing process, the liquids are first contacted in a zone of small dimensions in which turbulent mixing occurs and are then discharged into a zone of larger dimensions in which laminar flow is established. The two zones are so designed that there is a single piston operating in both zones and discharging the mixed product. The mixing head can be used to mix a polyol and a polyisocyanate during the formation of polyurethanes.

Abstract: A piston type pneumatic powered actuator (9) for operating a valve (10) of the expanding gate type wherein velocity of the piston-stem-gate drive train is maintained substantially constant in the latter stage of the actuator stroke. The actuator (9) includes an assembly of dual pistons (61,75) which are adapted to be driven by fluid pressure in one direction to operate the valve but are returned by spring means (66,67) when the fluid pressure is removed. A drive piston (61) directly connected to the actuator stem (23) is nested within a primary piston (75) which is not connected to the actuator stem (23) but moves the drive piston (61) when actuating pneumatic fluid is applied to the actuator (9). A stop (85) affixed to the primary piston (75) is adapted to cooperatively engage the actuator housing (40) to terminate the stroke of the primary piston (75) prior to termination of the stroke of the drive piston (61).

Abstract: A piston-driven valve includes a valve body provided with inlet and outlet openings, the communication between which may be interrupted by a clack-valve which is integral with a rod connected to a piston which is subjected to a valve-control pressure. A reversible head is equipped with an intake port for the control pressure, and the piston is located in the reversible head. A first reset spring named low pressure spring, directly bears on the piston, and a second reset spring is located between two calibrating bridges and selectively acts on the piston structure is provided for removing action by the second spring on the piston, in order to allow the valve to work with a low control pressure value.

Abstract: An improved control valve (20) for selectively connecting one or more inlet ports with one or more outlet ports to establish fluid communication there between is provided. This control valve (20) includes a housing (26) having a wall which defines at least one inlet port and at least one outlet port. A moveable rotor (25) is positioned within a chamber (30) defined within the housing (26). This rotor (25) includes at least one groove (33) having a configuration such that fluid communication can be established between a selected inlet port and a selected outlet port upon movement of the rotor groove (33) into alignment with the ports between which fluid communication is desired. Means are provided for driving or moving the rotor to the desired positions for establishing fluid communication between selected ports.

Abstract: Separate branch conduits extend from a common pump to two fluid power operated systems. One of the branch conduits supplies a relatively low volume of fluid through a pilot flow conduit to a steering control valve in one of the systems to adjust its operating pressure when the steering control valve is displaced from its neutral position. The other branch conduit delivers pressurized fluid directly to the steering control valve on a priority basis. A pressure regulating valve connected between the other branch conduit and the pilot flow conduit isolates the steering system from a higher pressure in the other fluid power operated system and adjusts the operating pressure in the steering system to meet steering load demands.

Abstract: A system for the high speed application of pressure sensitive labels to products includes an apertured label receiving head having both some vacuum apertures or ports and also some high pressure blower apertures or ports. Connected to the vacuum ports is a main vacuum conduit and similarly connected to the high pressure blower ports is a source of high pressure air which is applied in pulses to an input high pressure air conduit. The labels are dispensed across the faceplate of the unit and are held onto the faceplate by the vacuum applied to the vacuum apertures or ports. When it is desired to apply a label to the product, a pulse of high pressure air is applied to the unit and a shuttle valve within the faceplate or immediately adjacent thereto, is actuated by the high pressure pulse of air to slide across and close off the vacuum conduit, while high pressure air is simultaneously applied to all of the blower ports to blow the label across onto the product.

Abstract: The fluid valve comprises an integral housing made of forged steel, the housing having tubular end portions as fluid inlet and outlet, respectively, conical transition zones having a cone angle of at least 30.degree., and a central enlargement joined by said transition zones to said inlet and outlet ducts. The valve system is positively held between the transition zones. One of the transition zones may form the valve seat cooperating with an axially displaceable valve body.

Abstract: A hydraulic throttle valve is disclosed which includes a choke piston slideably mounted in a bore for movement between an open position and a closed position. A differential piston is coaxially mounted with respect to the choke piston, and a control valve is mounted for slideable movement in a second bore which is laterally spaced from and parallel to the first bore. The control valve is operated by an electromagnet to selectively direct a control fluid to either side of the differential piston, and thereby open or close the choke piston. A feedback spring arm interconnects the choke piston and the control valve, with the spring arm resisting the opening of the choke valve and with the resisting force being a function of the force applied to the control valve by the electromagnet. A balance of forces acting on the choke piston is thereby achieved, with the choke piston being opened to an extend functionally related to the magnitude of the input current to the electromagnet.

Abstract: A series of valves are disclosed which are specially designed for use in desiccant dryers. Each of the valves utilizes a housing (12), fabricated of standard pipe components and communicating flanges (13, 14) in conjunction with a poppet (24) and seat (20) arrangement. A support (30) fixed to one side of the interior of the housing carries an axial rod (23) to which the poppets (24) are mounted. Two- and three-way valves include a piston (36) and cylinder arrangement within the support to actuate the poppets. The poppet (224) of the check valve (200) is actuated automatically in response to pressure differentials across the poppet.

Abstract: A device for controlling the connection between a pressure medium source and a medium supply container is provided in a pressure medium operated system. The device includes a control valve with a housing formed with a longitudinal bore, in which a valve member is axially displaced between two end positions by pressure of the pressure medium. The valve member includes a piston and a seat portion facing a valve seat formed in the valve housing. The piston is of the diameter larger than that of the valve seat. A bore connected to the medium supply container is provided in the valve housing which is controlled by displacement of the piston.

Abstract: The exhaust valve has a valve member which opens away from the combustion chamber of the engine cylinder and which is biased for opening by the gas pressure prevailing in the combustion chamber. The valve is kept closed by an opposed hydraulic pressure which in a holding chamber acts on a holding piston secured to the spindle of the valve member. When the valve is to be opened, the pressure in the holding chamber is relieved and one or more valve controlled flow passages are opened, through which hydraulic liquid flows from the holding chamber to a reservoir defined by a further piston secured to the valve spindle. The two pistons are preferably of substantially equal size. When the exhaust valve is to be closed a hydraulic pressure is applied to a substantially smaller closing piston which is also secured to the valve spindle.

Abstract: A hydraulically operated valve which is operated open and closed by applying differential pressure to opposite end surfaces of an annular piston which moves a concentrically positioned valve operating plunger.

Abstract: A dissolution system for pharmaceutical solid oral dosage forms (medicinal tablets) comprising one or more open-top flasks for receiving a solvent media and the solid dosage forms to be tested, together with structure for delivering a solvent media into the flasks, structure for agitating the solvent media, structure for removing test samples, and structure in the form of a drain valve assembly at the bottom of each flask for removing residual solute and flushing the tank.

Abstract: In a pressure compensated flow control system a flow control valve has a valve element which is subjected to pulsating fluid pressure by which it is maintained in a state of dither about a mean position corresponding to the selected flow rate through the valve. The valve element is spring-biased towards a closed position and is displaced against the spring bias by an amount which is a function of the rate at which fluid is applied on one side of the valve element and the rate at which the fluid is bled away via an orifice.

Abstract: The plate valve has a housing forming an inlet spigot and an outlet spigot. A movable valve member provided with a closure plate and an orifice plate is movable radially of the spigots via servo-pistons which are rigidly connected to the valve member. The pistons are guided in cylinders disposed diametrically opposite one another on the spigots. The cylinders may be integrally formed with the plate valve housing or may be separably formed as cylinder heads.

Abstract: An automatic shutoff valve has a main inlet, a main outlet, and a main passage from the main inlet to the main outlet formed in a valve body. A piston chamber formed in the valve body has a valve seat in the main passage. A piston is movable back and forth through the piston chamber between a first position in engagement with the valve seat to close the main passage and a second position out of engagement with the valve seat to open the main passage. A first seal lies between the piston and the piston chamber to create on the piston a first area against which fluid pressure in the main passage acts to urge the piston toward its second position. An actuator is movable through a control chamber in fluid communication with one end of the piston chamber.

Abstract: A buffer valve or compensator for use in a margarine mold system to permit continuous operation of a positive discharge pump in the system, such valve including a valve housing connected to a conduit section for a flow line on the discharge side of the pump, a central discharge tube in the housing, a blind bore in the discharge tube terminating at the inward end of the tube, lateral discharge ports in the discharge tube into the bore at the inward end thereof, an annular piston in the housing around the discharge tube movable between a first inward end position covering the discharge ports and a second outward end position uncovering the discharge ports, a stop member limiting the outward movement of the annular piston, and ports in the closed outward end of the housing for introducing air under pressure to bias the piston toward the inward end position. The buffer valve is connected between the positive displacement pump, a chiller, and the mold machine.

Abstract: The invention relates to a method and a device for producing a solid-forming or foam-forming flowable reaction mixture by metered injection of flowable reaction components into a mixing zone from which the finished reaction mixture is discharged.

Abstract: The pressure fluid regulating valve has a central blind bore provided with axially spaced inlet and outlet openings, a sliding spool movable in the blind bore and defining two piston-like areas at its ends and an intermediate recessed portion having inclined walls and a central flange of a trapezoidal contour; a central bore in the spool interconnects via a throttling passage the end faces of the piston-like areas and communicates also with the recessed portion; the recessed area in the rest position of the spool interconnects the inlet and outlet openings and the inclination of respective sloping walls of the recessed portion and of the flange is selected so as to ensure a substantially uniform flow through the passage in any axial position of the spool.

Abstract: A spray assembly including an improved control valve is disclosed which is designed for heavy industrial usage to enable application of air and/or atomized liquids to be applied to the working surfaces of various types of forming apparatus such as molds and dies for example. The control valve utilized in the spray assembly of the present invention incorporates a piston actuated plunger assembly which is designed for extremely rapid operation whereby substantially maximum liquid fluid flow may be obtained almost instantaneously. Additionally, the spray assembly is designed so as to enable application of either one fluid alone such as blow air or both air and liquid. Also, the plunger is positioned so as to provide substantially unobstructed liquid flow into the air stream for atomization when in a fully open position thereby enabling large volumes of liquid to be applied within relatively short cycling time.

Abstract: A locking device is integrated in a coupling fixed on a ram cylinder for feeding the cylinder with a first fluid. The circulation of that fluid is controlled by a second fluid. The device has (1) a cylindrical member with a tightening head at a first end, a second threaded end to engage in the cylinder, and an intermediate portion between the two ends. The intermediate portion has an axial outlet passage to the cylinder, and a lateral opening terminating at the passage. The device has a coupling head with a through bore, and an internal passage for the first fluid. The bore is shaped to receive the intermediate portion and to couple the opening to the feed passage. The device has movable internal members to modify circulation of the first fluid by moving under the combined effects of a resilient element and the pressure of a second fluid applied to an external locking inlet.

Abstract: A back pressure control choke operates to automatically control and maintain a desired back pressure on the fluid passing through the choke. The choke housing has an inlet channel which intersects with an axial bore, part of which bore constitutes the discharge channel. An annular choke seat concentrically arranged in the discharge channel of the axial bore is adapted to receive an annular choke element. The choke element is affixed to a shuttle which is mounted on a fixed mandrel extending into the axial bore of the choke housing. The shuttle is dynamically sealed against the housing and mandrel such that a closed chamber is created in that portion of the axial bore opposite the discharge channel. The shuttle element is constructed to be fluid balanced such that it will move to achieve an equilibrium of pressure on its forward and rear surfaces.

Abstract: A compact valve and actuator includes a housing with a cylindrical bore which is open on one end of the housing and substantially closed at the second end except for an inwardly extending coaxial inlet tube. A cylindrical slide member is concentrically received between the outside of the tube and the inside of the bore and is provided with a piston-forming flange which is restricted in axial movement by a stop ring also located around the slide member midway of the bore. The second end of the bore and the stop ring form ends of a cylinder for the aforementioned piston-forming flange of the slide member. The slide member further includes valving apertures which cooperate with the stop ring to communicate fluid received via the inlet tube either to the open end of the bore, or via apertures in the stop ring to a by-pass.

Abstract: A relay valve for controlling fluid flow to and from a valve actuator included in a safety system for a flowline such as a production line of an oil or gas well. The relay includes a slide valve (60) which is manually pushed inwardly to the open or set position and held therein by pilot fluid which is also applied to the valve actuator. A visual indicator mounted on a knob (102) of the slide valve is operated by fluid applied to a passage (96) formed in the slide valve. A vent port (82) prevents pilot pressure from moving the slide valve from the closed position to the open position. A modified relay valve (150) has separate inlet ports (198 and 200) for receiving pilot fluid and actuator fluid and a vent port (206) which is in direct fluid communication with the pilot port in the closed position of the slide valve.