Abstract: A non-return valve for a vehicle hydraulic-power brake system. The non-return valve has a valve-seat part in the form of an apertured disk, onto which is pressed a valve cage in which a valve ball is disposed as shut-off member and a helical compression spring is disposed as valve spring. A bowl-shaped filter is secured in a depression in the valve-seat part opposite the valve cage.

Abstract: The present invention refers to a mandrel assembly for chemical injection in use in an oil well production string where the water depth can reach 3,000 m, exerting extreme hydrostatic pressures on the mandrel. The mandrel assembly is capable of dosing the chemical fluid flow rate to avoid some types of unwanted situations in the production string, mainly related to fouling. It has the characteristic of not using injection valves having small diameters, causing the annular space between the mandrel body and the inner part to ensure greater space for the flow of chemical fluid, thus reducing the likelihood of a possible plugging. Such characteristics ensure lower maintenance interventions, thus generating lower costs and increasing well reliability.

Abstract: Disclosed herein a check valve for a brake system includes a valve seat configured to be form an oil passage thereinside; an opening/closing member configured to open and close the oil passage inside the valve seat; an elastic member having one end elastically supporting the opening/closing member; a valve housing configured to support the other end of the elastic member and coupled to the valve seat; and a plunger that is accommodated in the oil passage and flows according to a flow of fluid generated during operation of the brake system.

Abstract: A brake control device adjusts a fluid pressure of a brake fluid in a wheel cylinder, and is provided with: a fluid passage which connects a master cylinder and the wheel cylinder; a first electromagnetic valve which is provided in the fluid passage; a second electromagnetic valve which is provided in the fluid passage between the first electromagnetic valve and the wheel cylinder; a fluid pump which is driven by an electric motor, suctions the brake fluid from the fluid passage at a suction part between the first electromagnetic valve and the second electromagnetic valve, and discharges the brake fluid to the fluid passage at a discharge part between the first electromagnetic valve UP and the second electromagnetic valve; a check valve which is provided between the fluid pump and the discharge part; and a controller which controls the first electromagnetic valve, the second electromagnetic valve, and the electric motor.

Abstract: A lift arm lifting and lowering mechanism cylinder case provided with a cylinder portion into which oil is fed, a piston slidable inside the cylinder portion to define a hydraulic chamber and receiving hydraulic pressure of the hydraulic chamber on a front surface, a safety valve provided to the piston to discharge the oil inside the hydraulic chamber to the outside when the hydraulic pressure of the hydraulic chamber becomes greater than or equal to a predetermined value, and a lift arm supported by the cylinder case and rotatable in conjunction with movement of the piston, in which the piston includes an oil passage allowing communication between a rear surface of the piston and the front surface, and the oil passage includes a containing portion provided to open on the axially front surface side and capable of containing the safety valve, and a non-containing portion provided on the axially rear surface side relative to the containing portion and incapable of containing the safety valve.

Abstract: A manifold assembly configured for integration with a joint cover apparatus in a ducting system to detect leaking gas comprises an elastomeric manifold block having a substantially circular inlet aperture and one or more gas passages fluidly coupled to the inlet aperture. The assembly includes a flow control valve configured to maintain a closed state in which a component of the flow control valve sealingly engages with the inlet aperture to preclude gas at the inlet aperture from flowing into the one or more gas passages until said gas reaches a pressure corresponding to a pressure threshold. The assembly also includes at least one aperture control plate disposed substantially proximate to a lower end of the manifold block and including a substantially circular opening. The aperture control plate is adapted to maintain the substantial circularity of the inlet aperture, so as to ensure a substantially fluid-tight seal.

Abstract: A check valve includes a ball and a seat. The seat includes a body and a hole extending through the body. The hole is smaller in diameter than the ball. The body of the seat is formed from ultra-high-molecular-weight polyethylene. The ultra-high-molecular-weight polyethylene of the seat has an ASTM D648 heat deflection temperature of 46.7° C. at 1.8 MPa.

Abstract: A personal vaporizer is configured to be usable both for non-liquid vaporizing media and for liquid vaporizing media. In some embodiments an electrically conductive check valve blocks vaporizing media from leaking out of air intake apertures during periods of nonuse, and delivers electric power to a heating element during use. In some embodiments, no wick structures extend into a fluid chamber, but a wick extends from a wick holder downstream of the fluid chamber to a vaporizing chamber.

Abstract: A blowout preventer (“BOP”) for sealing against an object includes a housing comprising a bore extending through the housing with the object being extendable through the bore. The BOP further includes a packer assembly movably positioned within the housing and configured to form a seal within the housing. The packer assembly includes a body comprising an elastomeric material and an insert at least partially positioned within the body. The insert comprises a harder material section and a softer material section with respect to the harder material section and configured to deform against the object.

Abstract: A downhole system having a chemical injection valve assembly configured to inject at least one chemical from a chemical injection line into a downhole tubing. The chemical injection valve assembly includes a passive access control mechanism configured to reveal a first port to the tubing in a first condition and block the first port in a second condition. The passive access control mechanism including a movable piston, wherein in the first condition the piston is exposed to a first pressure source on a first side of the piston and to a second pressure source on a second side of the piston. The first pressure source is from within the tubing and the second pressure source is from outside of the chemical injection line and the tubing. Also included is a method of chemical injection in a downhole system.

Abstract: The invention relates to a safety valve for a cryogenic insulated gas cylinder, which comprises a valve body, and the valve body further comprises a gas inlet flow channel, a valve seat, a slide way, a valve core and a spring, a gas inlet connecting thread and an adjusting nut. An adjusting nut exhaust hole set on said adjusting nut, a spring set between the said adjusting nut and a spring bracket with an exhaust hole. A valve assembly further comprises the valve core, a plurality of guide rings, a positioning steel ball and a valve flap, a valve core exhaust hole is provided in the valve core. The safety valve has high stability in discharge pressure and return pressure, high repeatability and good sealing performance, and is firm in structure, difficult to be damaged and high in safety.

Abstract: In a reciprocating piston pump, piston 34 has first or upper end 48 and second or bottom end 50 having inlet 52 and outlet 54 bores respectively located therein. Inlet check 32 is located in bore 52 while outlet check 42 is located in bore 54. As can be seen in FIG. 3, each of bores 52 and 54 branches into three (in the preferred embodiment) flow paths which alternate and are intertwined. It is the unique flow paths incorporating both the inlet and outlet check valves in the piston that are the key features of the invention.

Abstract: A flamer may be used to sterilize poultry litter, soil, concrete, etc. The stationary or mobile flamer disclosed comprises a hood to contain the heat, an external frame, and burners. A fuel tank may be carried on the flamer or on a tractor. An additional embodiment provides for mounting the flamer on wheels, permitting the unit to be towed by a truck, four-wheeler, tractor, etc. The burners are adjustable as to angle, and fueling rate. A pressure in the fuel system is controlled by selectively switching between the liquid and vaporous components of the fuel. By limiting how low the pressure may fall, the flow of fuel from the tank to the torches is more consistent.

Abstract: A valve member having a valve part and a piston part is accommodated in a piston accommodation cylinder part of a case reciprocatably, and a damper chamber that is substantially a sealed space is formed in an anti-valve seat side in the valve member so that fluid flows without flowing via the damper chamber. Accordingly, since the fluid does not pass through the damper chamber, a fluid force that occurs in the piston part due to a fluid flow does not change easily, thus it becomes difficult to increase hunting at the valve members. Moreover, in a vibrational component in the valve member reciprocating direction of the valve members, amplitude of the vibration can be decreased by a damping force generated in the damper chamber.

Abstract: In a check valve in which a valve part is disposed in a valve part accommodating recess movably relative to a piston part, among the valve part accommodating recess, an anti-valve seat side accommodation space formed between a surface of the valve part accommodating recess in an anti-valve seat side of the valve part and a wall surface of the valve part accommodating recess are communicated to exit side fluid passages.

Abstract: An overpressure relief valve assembly includes an outer housing having an inlet at a first end opening to an inlet cavity and an outlet at an opposite second end opening to an outlet cavity, and a valve located in the outer housing, the valve including a valve housing that is fixed with respect to the outer housing and an actuator movable within the valve housing to alternatingly cut off and allow communication between the inlet cavity and the outlet cavity.

Abstract: A valve (101) that can be used as a pressure limiter, for example in a sanitary supply line. The valve (101) according to the invention includes a valve housing (1), a fluid line piece (2) being provided in the housing interior thereof, the downstream side circumferential edge area thereof forming a valve seat (3) for a valve body (4), wherein the valve body (4) can be displaced between an open position and a closed position, in which closed position the valve body (4) acts on the downstream circumferential edge area of the fluid line piece (2), by the pressure of the fluid flowing in through the fluid line piece (2) on one side, and a downstream side pressure acting on the valve body (4) opposite to the regular flow-through direction on the other side.

Abstract: The invention relates to a pressure limiting valve, in particular for placement in a return line of a common-rail-system of a combustion engine, with an elongate valve housing having an axial inlet opening present on one front end, and at least one outlet opening axially separated from the inlet opening. An interior valve seat for a ball-shaped valve body connects to the inlet opening, whereby a valve piston is positioned between the valve body and a closing spring producing a closing force. An integrated hydraulic throttle dampens the movement of the valve piston in the valve closing direction. A valve-seat insert part has a ring-shaped body with an inlet opening formed on a front end, with the conically expanding valve seat connecting to the inlet opening, as well as with a throttle section with a cylindrical interior area connecting to the valve seat.

Abstract: A flow-through pressure regulator includes housing structure having a fuel inlet and a fuel outlet. A seal band is defined by the housing structure. A valve element is movable between open and closed positions. The valve element has a sealing surface that engages the seal band in the closed position to prevent fuel from passing from the fuel inlet to the fuel outlet. A compression spring is disposed in the housing structure. The spring is constructed and arranged to bias the valve element to the closed position in opposition to pressure exerted on the valve element by fuel at the fuel inlet. A guide member is associated with the valve element and is constructed and arranged to align the valve element with respect to the seal band. A calibration member is associated with an end of the spring and is constructed and arranged to pre-set compression of the spring.

Abstract: A flow control valve for use in oxygen systems. The flow control valve has a body within an inlet and an outlet. A seat is located within the body and a ball retainer is located within the body. The ball retainer is able to capture a ball. The flow control valve also has biasing means connected to the ball retainer. Furthermore, the biasing means is movable between a flow and a non-flow position. The ball retainer is in a closed position when the ball, captured by the ball retainer, engages the seat to prevent gas flowing through the seat.

Abstract: A portable Brinell metal hardness tester has a test head mounted in a carriage, movable vertically along elevating screws, and includes an adjustable valve for relieving hydraulic pressure within the test head where the valve includes a stem, an interior member, and an intermediate member.

Abstract: A fluid flow detection device includes a housing of non-magnetic metal, a flow passage through the housing and a valve seat in the flow passage. A magnetic valve element emits a magnetic field. The valve element is movable relative to the valve seat between a closed position blocking fluid flow through the flow passage and an open position allowing fluid flow through the flow passage. The magnetic valve element is biased toward the closed position. A magnetic field enhancer is movable with the magnetic valve element for enhancing the magnetic field. A magnetic field sensor on the housing is operable to signal a change in position of the valve element as it moves between its open and closed positions.

Abstract: The invention relates to a pressure limiting valve, in particular for placement in a return line of a common-rail-system of a combustion engine, with an elongate valve housing having an axial inlet opening present on one front end, and at least one outlet opening axially separated from the inlet opening. An interior valve seat for a ball-shaped valve body connects to the inlet opening, whereby a valve piston is positioned between the valve body and a closing spring producing a closing force. An integrated hydraulic throttle dampens the movement of the valve piston in the valve closing direction. A valve-seat insert part has a ring-shaped body with an inlet opening formed on a front end, with the conically expanding valve seat connecting to the inlet opening, as well as with a throttle section with a cylindrical interior area connecting to the valve seat.

Abstract: The high-pressure pump has at least one pump element which has a pump plunger which is driven in a reciprocating motion and defines a pump working space into which fuel is drawn in from a fuel feed via an inlet valve during the suction stroke of the pump plunger and from which fuel is displaced into a high-pressure region via an outlet valve during the delivery stroke of the pump plunger. The inlet valve and/or the outlet valve has a valve member at least approximately in the shape of a ball which acts as a sealing surface with a valve seat arranged in a valve housing. The valve member, in its open state, is lifted with its sealing surface from the valve seat, a first cross section of flow is cleared between the valve member and the valve seat, and downstream of the first cross section of flow, a second cross section of flow is formed between the valve member and the valve housing.

Abstract: An improved assembly of a foam soap dispenser control valve includes a lower casing, an upper casing and a valve body. In addition, a spring is installed in a protruding tube of the valve body, and a steel ball is disposed at the tip of the spring, and a bushing is sheathed onto the external periphery of the protruding tube for abutting the steel ball tightly against the top of the protruding tube and the internal side of the upper edge of the bushing, and a hollow joint bushing is protruded from the top of the upper casing, and the top of the joint bushing is a closed end, and a soap feeding inlet is disposed on a side of the bottom of the joint bushing, such that the upper casing and the lower casing can be engaged by screws to form the improved assembly of the soap dispenser control valve.

Abstract: A check valve includes a modulation and/or anti-oscillation feature which, in one aspect, modulates the position of the check valve ball relative to the valve seat to maintain the ball in a continuous flow position allowing pressurized fluid flow past the ball while preventing contact between the ball and the valve seat. In another aspect, an increased mass is selectively coupled to or forms a part of the movable valve member to dampen oscillations of the movable valve member in an open fluid flow position without contact with the valve seat.

Abstract: An apparatus for controlling the flow of a medium. The apparatus comprises a base having a plurality of arms extending from the base. The base and arms define a cage. A valve member is positioned within the cage. The apparatus further includes a biasing housing disposed within the base, and wherein a spring is disposed within the biasing housing. The apparatus further includes a passageway formed about the valve member when the valve member is opened so that the medium flows on the outer portion of the biasing housing, and wherein the flow of the medium in an opposite direction urges the ball into engagement with the valve seat. When the valve is open, the medium collapses the spring and the valve member blocks the flow of the medium from entering the biasing housing. A method of drilling a well with the flow valve positioned on a work string is also disclosed.

Abstract: Disclosed is a pressure control valve (8) for a hydraulic device, particularly a fuel supply system of a motor vehicle, comprising a valve seat (10) that is disposed between a valve member (13) and a spring element (16) for biasing the valve member (13) counter to the valve seat (10). The valve member (13) and the spring element (16) are interconnected via a traction element (14) such that the valve member (13) is reliably guided towards the valve seat (10) without using any additional guiding elements.

Abstract: In an improved floating ball check valve including a body having an outlet port, a cap, having an inlet port, joined with the body, a ball guide slidably received within the body and having a ball pocket for receiving a sealing ball, a biasing spring for biasing the ball toward the inlet port, an annular seat retainer in the cap and a generally ring-shaped seat, of non-resilient plastic material of preferably thermoplastic or fluoroplastic composition, substantially received within a conical bore within the cap and retained therein via the seat retainer, with the spherical surface of the ball being urged into a sealing engagement with an arcuate/spheric sealing surface of the seat having a radius slightly larger than the radius of the sealing ball, with the noted seat materials and geometries permitting seat self-compensation for pressure and temperature. An improved manufacturing method is also set forth.

Abstract: A multi-function fluid flow control device is disclosed. A body houses a filter screen, a check valve and an orifice plate mounted on a frame which is removable from the body as a unit through an opening in the body sealed by a removable plug. The orifice plate is removable from the frame to permit different sized orifices to be fitted. An inlet in the body conducts pressurized fluid through the filter screen, through the check valve and then out through an outlet in the body, both the inlet and outlet being adapted for convenient connection to a piping network. An opening in the body in fluid communication with the inlet and sealable by a removable plug allows the screen to be flushed for removal of debris.

Abstract: A method of controlling a pressure control valve assembly (69) to control a control pressure (43,71) in a system (11) including a source (47,49) of pressurized fluid. The control valve assembly is operable to vary the control pressure in response to variations in an electrical input signal (87) to an electromagnetic coil (81). The control valve assembly defines an inlet (77) in communication with the control pressure, an outlet (93) in communication with the low pressure, and a valve seat (89) disposed intermediate the inlet (77) and the outlet (93). A poppet valve member (91) is biased toward the valve seat by a biasing means including an armature (95), the biasing force being generally proportional to the input signal to the coil. The method comprises the steps of selecting a predetermined, minimum pressure for the control pressure corresponding to a minimum condition of the system.

Abstract: The check valve according to the invention significantly reduces the generation of noise by producing an asymmetrical circulation around the closing body causing a force resulting from the flow and acting on the closing body to have a transverse component in relation to the opening direction, as a result of which increased friction and damping are generated in the closing body guide. The closing body may be asymmetrically embodied, or the housing wall encompassing the closing body may be provided with a conduit extending in the opening direction over at least a part of the travel path of the closing body.

Abstract: A relief valve is provided with an elastic body seal sealed into an annular gap between a ball receiver and a valve hole, and is slidably in contact with an inner periphery of the valve hole such that the elastic body seal is not compressed in an axial direction of the ball receiver.

Abstract: In a check valve of the present invention, when a pressure action direction of a fluid on a valve body is assumed to be X, a spring receiving surface that abuts with a seat surface that is at one end in an axial direction of the helical compression spring is made to incline with respect to a surface perpendicular to the pressure action direction X. Accordingly, an urging force of the helical compression spring on the valve body acts obliquely with respect to the pressure action direction X. Thus the valve body is pressed to a side wall surface when the valve is opened, and vibration of the valve body is inhibited. Accordingly, it is possible to embody the invention with an extremely simple structure in which the spring receiving surface is inclined with respect to the surface perpendicular to the pressure action direction X.

Abstract: A transmission member that transmits urging force of a helical spring to a valve body is disposed between the valve body and the helical spring. The transmission member changes a direction of an urging force transmitted to the valve body such that the urging force is oblique to a pressure action direction X. Accordingly, when a check valve is in an open state, the valve body is pressed against a side wall and thus vibration of the valve body is inhibited. Further, when the check valve is in a closed state, an angle ? formed by the direction of the urging force transmitted to the valve body and the pressure action direction X is set to be between 8 degrees and 45 degrees. Accordingly, it is possible to simultaneously realize a fluid path opening/closing function and a valve body vibration inhibition function.

Abstract: A diaphragm head with a high energy content of the oil space (pressure×volume) has a strong negative influence on the corresponding behavior of the oil overflow valve. The reaction of the valve leads to an undesirable increase in the opening time by which more oil is discharged than oil introduced by means of a compensation pump. This has the result that after multiple strokes the diaphragm is not driven to its dead position. With this, all of the compressed gas is not expelled which is accompanied by a rapid decrease of the suction capacity. The solution to this problem according to the present invention is achieved by means of a flow-interrupting edge formed at the junction of the valve seat and a restriction piece at the outlet side by which the operating forces of the valve spindle are sharply reduced. With this the effective closing force of the spring, as the dominant force component, leads to the desired fast closing time to the valve.

Abstract: A multiple pressure direct acting relief valve is disclosed. The multiple pressure relief valve comprises an actuating cylinder, a relief valve and an adjustment screw interconnecting the actuating cylinder and the relief valve. The relief valve includes a low pressure spring which biases a poppet valve arrangement permitting the poppet valve arrangement to be actuatable at a first pre-determined pressure. The actuating cylinder includes a piston that is biased by a high pressure spring causing an additional compressive force to be applied to the poppet valve arrangement through an actuating rod received through the adjustment screw. When pressure is applied to the piston within the actuating cylinder, an additional compressive force is applied by the high pressure spring and the actuator rod to the poppet valve arrangement causing the poppet valve arrangement to be actuatable at a second pre-determined pressure.

Abstract: A differential assembly for a motor vehicle comprises a differential case rotatably supported in an axle housing, opposite output shafts drivingly connected to the differential case, a friction clutch pack for controlling the differential action, and a hydraulic clutch actuator for selectively fictionally loading the clutch pack. The hydraulic clutch actuator includes a variable pressure relief valve assembly to selectively control the friction clutch pack. The variable pressure relief valve assembly includes a valve closure member, a valve seat complementary to the valve closure member, and an electro-magnetic actuator for engaging the valve closure member and urging thereof against the valve seat with an axial force determined by a magnitude of an electric current supplied to the electro-magnetic actuator so as to selectively vary a release pressure of the pressure relief valve assembly based on the magnitude of the electric current.

Abstract: A gap 11 between a flange 4A of a bail support member 4 and the inner circumferential surface of a sleeve member 7 functions as an orifice for restricting an oil flow downstream of a seat hole (6B). The movement of the ball support member 4 is stabilized, pressure is generated in a chamber 9 downstream of a seat hole 6B, and the override characteristics of the relief valve 1 are improved.

Abstract: A check valve allowing one-way fluid flow is disposed at an outlet side of a pressurizing pump. The check valve includes a valve seat and a valve body for opening and closing a fluid passage in response to a fluid pressure supplied to the check valve. The valve body is biased by a biasing member such as a spring in a direction to close the fluid passage. To suppress vibration of the valve body occurring at its open position due to pulsating fluid pressure supplied from the pump, a biasing force is applied to the valve body in a direction slanted from the fluid pressure-imposing direction. The valve body is pushed against a sidewall by a lateral component included in the biasing force, and thereby the vibration of the valve body is suppressed.

Abstract: A diaphragm head with a high energy content of the oil space (pressure×volume) has a strong negative influence on the corresponding behavior of the oil overflow valve. The reaction of the valve leads to an undesirable increase in the opening time by which more oil is discharged than oil introduced by means of a compensation pump. This has the result that after multiple strokes the diaphragm is not driven to its dead position. With this, all of the compressed gas is not expelled which is accompanied by a rapid decrease of the suction capacity.

Abstract: The present invention provides a pressure relief valve, which achieves a reliable sealed structure in a valve holder 31 without the valve holder 31 jutting far out from a common rail, assures stability of operation of a valve spring 11 in a valve holder 31, and is capable of being manufactured at low cost and can be made compact.

Abstract: The pressure regulating valve (2) proposed here can be designed with the aid of the outflow throttle restriction (28) downstream of the valve seat (22) in such a way that the pressure regulating valve (2), as the fluid flow becomes greater, sets or adjusts a smaller pressure difference at the pressure regulating valve (2), as a result of which the line losses that can never be avoided can be compensated for. The pressure regulating valve is suitable in particular for a fuel supply system of a motor vehicle having an internal combustion engine.

Abstract: A preinjection valve with a valve body, in which an inlet conduit is embodied which can be filled with fuel at high pressure via a high-pressure pump. An outlet conduit is embodied in the valve body and discharges laterally into the inlet conduit and communicates with a fuel injection valve via a high-pressure line. A preinjection valve member is guided sealingly in the inlet conduit and is moved counter to a closing force by the fuel pressure in the inlet conduit and after executing a preinjection stroke (hv) comes to rest on a deflection valve member guided, likewise sealingly, in the inlet conduit. By the motion of the preinjection valve member, a preinjection quantity is pumped into the outlet conduit and delivered to the fuel injection valve.

Abstract: The invention relates to a radial piston pump for high-pressure fuel delivery in fuel injection systems of internal combustion engines in a common rail injection system having a drive shaft that is supported in a pump housing. The drive shaft is eccentrically embodied or has a number of cam-like projections in the circumference direction, and a number of pistons are arranged radially in relation to the drive shaft. Each piston reciprocates a respective cylinder chamber and is moved in a reciprocating fashion in the cylinder chamber when the drive shaft rotates. A spring-preloaded check valve is assembled on the intake side and on the high pressure side, and a component that includes a through opening constitutes the respective cylinder chamber. A high-pressure delivery opening leads away from the cylinder chamber and in the sealing seat of the high pressure side check valve, opens out into a mounting opening of the component. The mounting opening contains the valve components.

Abstract: The present invention provides a pressure relief valve, which achieves a reliable sealed structure in a valve holder 31 without the valve holder 31 jutting far out from a common rail, assures stability of operation of a valve spring 11 in a valve holder 31, and is capable of being manufactured at low cost and can be made compact.

Abstract: On a recreational vehicle, a water supply coupling is provided to permit the hookup of an external water supply to the plumbing of the recreational vehicle. The coupling selectively permits one-way flow into, but not out from, the plumbing, thereby maintaining the pressurized integrity of the plumbing system. The coupling has a movable check member which may be seated against an annulus to create a seal. In various disclosed embodiments, the check member may be a check ball, a mushroom-shaped check member having a hemispherical seating portion and a stem, and a two-piece check member.

Abstract: High pressure check valves and fittings, including button head fittings, sealant fittings, and lubrication adapters, that are equipped with dynamically self-centering plungers. Each metallic fitting comprises a fluid inlet and a fluid outlet. The inlet end of each may be configured to be mechanically engaged by high pressure hoses, grease guns, or the like. The outlet end is configured, as by threading, for coupling to the desired application. The inlet and outlet are in fluid flow communication, and meet at an internal valve seat. A steel ball forms the check valve element. The ball is dynamically controlled and centered by a dynamic plunger coaxially and slidably disposed in the fitting. A return spring coaxially mounted on the plunger normally urges the ball and the plunger towards the valve seat to close the fitting. A plunger crown is integral with an elongated, dual-diameter shaft. A conical depression in the crown seats the ball for centering.