Abstract: A system and method to prepare and dispense a N2 or N2/CO2 gas infused chilled beverage is provided. The beverage may be any non-carbonated liquid and in one embodiment the beverage is coffee. The dispensed N2 or N2/CO2 gas infused chilled coffee has a unique appearance and enhanced flavor and aroma. The system may be provided as a self-contained unit.

Abstract: An explosion protection valve for decoupling system parts or workpieces for the installation in a pipeline, comprising a housing, a closing body which is axially guided inside the housing on a guide rod and can be shifted from a defined open position into a sealing closed position in the event of a pressure or suction wave in the pipeline in at least one closing movement direction, a spring assembly, which is in operative connection to the closing body, on the guide rod for holding the closing body in the open position, a sealing ring on the inner side of the housing, against which the closing body can be pressed in its closed position, and a receiving pocket, which is applied to the inner side of the housing and is preferably open counter to the closing movement direction (SB) of the closing body, for holding the sealing ring.

Abstract: Fluid valve apparatus having enclosed seals are disclosed. An example fluid valve includes a movable flow control member positioned between an inlet and an outlet of a fluid flow passageway of the fluid valve. A retainer is removably coupled to the flow control member such that the retainer and the flow control member define a sealing cavity when the retainer is coupled to the flow control member. A seal is positioned within the sealing cavity to define a sealing surface of the flow control member. The seal has an inner core composed of a first material, where the core is substantially encased with a sheath composed of a second material different than the first material. The retainer clamps the seal to the flow control member.

Abstract: An assembly can include a valve seat for an exhaust bypass valve of a serial turbocharger system; and a gasket that includes a planar portion that defines a perimeter and that includes a tab that extends from the perimeter of the planar portion for engagement with the valve seat to secure the gasket to the valve seat. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

Abstract: The invention relates to the simple and safe construction of a high-pressure connection (1) for transferring gaseous and/or liquid media, in particular for the refuelling of vehicles with hydrogen. According to the invention, the high-pressure connection (1) comprises a housing (2) with a media passage (P) and a leaktight piston (3) of which the front end is disposed in a sealing manner with respect to an annular seal. The seal (4) has a seal support (4a) in which is inserted a sealing insert (4b), the sealing support (4a) consisting of a harder plastics and the sealing insert (4b) consisting of a softer plastics.

Abstract: Valve seat assemblies are disclosed herein. An example apparatus includes a valve seat assembly including a cage and a valve seat coupled to the cage. The valve seat assembly is to be disposed in a valve body. The example apparatus also includes a seal having a first side, a second side, a third side and a fourth side. The first side, the second side and the third side are to be in contact with the valve seat assembly, and the fourth side is to be in contact with the valve body.

Abstract: A slide gate having a frame assembly including an intermediate cross member coupled between a first and second gate guide members defining a corresponding pair of side channel elements each containing an elongate side seal which abut opposed ends of an elongate top seal secured to the intermediate cross member to seal a gate slidely engaged in the pair of side channel elements.

Abstract: Improved flow control assemblies for fluid systems (e.g., industrial and/or commercial systems) are provided. More particularly, the present disclosure provides for advantageous wafer check valve assemblies for fluid systems (e.g., piping systems or the like). The present disclosure provides for advantageous wafer check valve assemblies that include an angled sealing surface, which allows the disc member to seal even with the valve assembly in the horizontal position, and/or to seal without the aid of a spring. Improved, convenient, low-cost and/or effective systems and methods for utilizing improved wafer check valve assemblies in fluid systems (e.g., piping systems or the like) are provided.

Abstract: A terminal valve having a cone (9) that communicates with a valve seat (10) of a seat ring (19) and cooperates with a veil (12) to control flow. The valve seat (10) and the veil (12) together form a sealing element, which seals against the cone (9) as well as the valve body (1). The cone (9) has a cylindrical portion (46) with slits (49, 50) that form a flow passage area which allows a flow that corresponds to a modified logarithmic function.

Abstract: A flush valve has a valve body having an inlet and an outlet, and a piston disposed in the valve body between the inlet and the outlet. A surface is disposed in the valve body for seating the piston. The surface tapers inwardly as it passes into the outlet wherein the taper improves the flow characteristics of fluid passing by the taper thereby minimizing water hammer and leakage therethrough.

Abstract: A valve in which durability of a sealing member made from an elastic material can be increased and sealing capability can be advantageously maintained over a wide range from a large differential pressure to a low differential pressure. A valve (100), in which a valve disc (1) and a valve seat (2) are brought into close contact via a sealing member (5) composed of an elastic material and provided at the valve disc (1) or valve seat (2), comprises a throttle section (30) defined by the shape of at least one of the valve disc (1) and valve seat (2). The throttle section (30) narrows a flow passage formed between the valve disc (1) and valve seat (2) and is provided near the sealing member (5). The flow passage narrowed by the throttle section (30) is so set that narrowing preferentially proceeds in the flow passage in close proximity to the sealing member (5) during the closing operation of the valve disc (1).

Abstract: A valve seat for use in a high pressure pump comprises an inner portion force fit within an outer portion. The outer portion has a fluid plenum at an outer peripheral surface. Fluid passages extend radially inwardly to communicate with a valve recess in the inner portion. A seal housing for a high pressure pump comprises an outer portion and an inner portion. The inner portion is force fit within the outer portion. The inner portion has an inner bore having a first location to receive seal packings, and a second location to receive valve spring structure. The inner portion has a curved surface that bottoms out against a curved surface within the outer portion.

Abstract: A valve (20) is provided for sealing an evacuation port (16) in a port area (18) of a wall structure (12) of a container. The valve (20) comprises a casing (22) having a shell portion (30) which is deformable from an open condition, whereat the shell portion (30) forms a chamber (32) over the port area (18), and a closed condition, whereat the shell portion (30) contacts the port area (18). When the shell portion (30) is in its open condition, gas exits from the chamber (32) through gas-releasing holes (24) in the casing (22). When the shell portion (30) is deformed to its closed condition, a port-sealing adhesive (26) adheres to the port area (18) to thereby seal the evacuation port (16).

Abstract: A check valve for a combustion engine fuel system includes a polymeric poppet valve including a valve stem and a valve head that terminates the valve stem. A valve seat is adapted for cooperation with the valve head of the poppet valve, and includes a valve seat body and an elastomeric valve seat seal supported by the valve seat body and adapted for sealing against the valve head of the poppet valve. The check valve is particularly adapted for use with a fuel pump within a fuel system.

Abstract: The valve sealing system for a reagent package includes an annular cylindrical gasket seated in a channel formed in the package. A rocker valve on the package pivots relative to the annular cylindrical gasket which surrounds an opening to the chamber of the reagent package. The annular channel includes a radially inner peripheral channel sidewall, a radially outer peripheral channel sidewall, and a bottom portion. An inclined peripheral wall portion of the channel intersects one of the channel sidewalls at an obtuse angle and the bottom portion of the channel. When the rocker valve is in a valve closed position it engages the annular cylindrical gasket to provide a substantially leak-tight seal.

Abstract: A valve in which durability of a sealing member made from an elastic material can be increased and sealing capability can be advantageously maintained over a wide range from a large differential pressure to a low differential pressure. A valve (100), in which a valve disc (1) and a valve seat (2) are brought into close contact via a sealing member (5) composed of an elastic material and provided at the valve disc (1) or valve seat (2), comprises a throttle section (30) defined by the shape of at least one of the valve disc (1) and valve seat (2). The throttle section (30) narrows a flow passage formed between the valve disc (1) and valve seat (2) and is provided near the sealing member (5). The flow passage narrowed by the throttle section (30) is so set that narrowing preferentially proceeds in the flow passage in close proximity to the sealing member (5) during the closing operation of the valve disc (1).

Abstract: A by-pass valve that includes a housing defining a chamber therein, and a by-pass valve port and a first port communicating with the chamber. The by-pass valve port has a central axis and a peripheral valve seat. The by-pass valve also includes a valve assembly comprising a central shaft disposed along said central axis, and an annular ring slidably mounted on the central shaft for movement between a closed position in which the annular ring engages the valve seat and an open position in which the annular ring is spaced apart from the valve seat, the annular ring having a cylindrical inner surface surrounding the central shaft with a first circumferential rib extending inward from a portion of the inner surface and slidably engaging the central shaft.

Abstract: The invention relates to a double seat valve with cleanable seats, which is improved with regard to the prior art in that a discharge possibly free of turbulence of the seat cleaning flow into and out of the leakage cavity is ensured and a direct admission of the seat areas, which would increase pressure, is safely avoided.

Abstract: A flow control device having a control member for forming a seal with another part of the flow control device. The control member having a base material and a portion or surface that is a softer or more deformable than the base material or the portion of the control device that the control member forms a seal with. The differences in hardness and/or the ability of the control member portion to deform, aids in forming the seal.

Abstract: A flow control device having a control member for forming a seal with another part of the flow control device. The control member having a base material and a portion or surface that is a softer or more deformable than the base material or the portion of the control device that the control member forms a seal with. The differences in hardness and/or the ability of the control member portion to deform, aids in forming the seal.

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 valve is disclosed having an inlet duct aligned with an outlet duct and an angularly oriented elliptical seat positioned between them. A pressure chamber faces the seat. A pivoting valve closure member is positioned between the pressure chamber and the seat. An asymmetrical rolling diaphragm is attached to the closure member and defines part of the pressure chamber. A seat engaging surface on the side of the closure member opposite the pressure chamber is sealingly engageable with the seat to close the valve. The valve closure member is pivoted into the closed positioned by pressurizing the pressure chamber. The valve remains closed against hydraulic pressure in the inlet duct. The valve is permitted to open by de-pressurizing the pressure chamber, allowing the closure member to pivot out of engagement with the seat. Fluid may then flow from the inlet duct to the outlet duct.

Abstract: Thin chamber diaphragm-operated fluid handling devices, including thin chamber pumps and thin chamber valves, facilitate device compactness and, in some configurations, self-priming. Diaphragm actuators of the thin chamber devices either comprise or are driven by piezoelectric materials. The thinness of the chamber, in a direction parallel to diaphragm movement, is in some embodiments determined by the size of a perimeter seal member which sits on a floor of a device cavity, and upon which a perimeter (e.g. circumferential or peripheral portion) of the diaphragm actuator sits. The diaphragm actuator is typically retained in a device body between the floor seal member and another seal member between which the perimeter of the actuator is sandwiched. The devices have an input port and an output port.

Abstract: The invention provides a vacuum gate valve for closing off an opening. The vacuum gate valve can have a valve plate that can be turned so that the alignment of the valve plate will adapt to a valve seat when the valve plate is pressed against the valve seat.

Abstract: A surge prevention valve may be used to prevent the formation of an initial surge of high pressure. The valve may be located, for example, between a high pressure gas cylinder and a medical pressure regulator. The valve is provided with first and second valves located within a housing and integrating a pressurization orifice. The initial opening of the valve in an axial direction enables gas to flow through the pressurization orifice at a first flow rate. The full opening of the valve in the axial direction enables the gas to flow through the second valve at a second flow rate, which is much higher than the first flow rate. The controlled pressurization of the gas through the orifice delays the time during which the gas reaches full recompression. The valve may be further provided with a vent for venting pressurized gas away from a nominally closed top surface of the lower valve element.

Abstract: A valve assembly including a housing having a flow channel and an annular surface surrounding the flow channel, a slide plate movable to a closed position, and a seal ring positioned between the annular surface and the slide plate. The seal ring includes a first and second sides, a first surface extending between the first and the second sides and facing towards the annular surface of the housing, and a second surface axially spaced from the first surface and extending between the first and the second sides and facing towards the slide plate. The second surface includes a continuous annular sealing portion for contacting the slide plate when the seal ring is biased against the slide plate so that a fluid-tight seal can be formed between the continuous annular sealing portion and the slide plate, and at least one passageway positioned between the annular sealing portion and the second side.

Abstract: The device described herein is a valve suitable for the control or shut-off of fluid flow in a piping system. It comprises a valve housing having inlet and outlet ports and a cylindrical bore whose axis is slanted at about 45 degrees in relation to the axis connecting said inlet and outlet ports. A ball or closure member being slindingly arranged within said slanted bore and being capable of making tight contact with a flexible and suitably retained metal seal interspaced between said inlet and outlet ports. Additional means allow for the ball or closure member to connect to a conventional actuating device having linear output motion.

Abstract: A vacuum valve comprises a wall with a valve opening and a valve seat, a valve plate which is pressed against the valve seat in the closed state, an elastic sealing ring which is arranged at the valve plate or at the valve seat and, in the closed state of the valve, is pressed by a pressing force against a sealing surface arranged at the valve seat or at the valve plate and seals the valve opening, and a supporting ring which is made of plastic and which is arranged at the valve plate or at the valve seat and, at least in the closed state of the vacuum valve, lies closer to the valve opening than the sealing ring, viewed from the sealing ring, and limits the pressing force acting on the sealing ring in the closed state of the vacuum valve.

Abstract: A seal for a poppet valve of an integrated pressure management apparatus, a valve system using the poppet valve seal, and a method of cleaning debris off of a poppet valve. The poppet valve is movable between an open position permitting fluid flow through an aperture in a housing and a closed position preventing fluid flow through the aperture. The seal includes an annular body having a first sealing surface fixed to the housing and a second sealing surface confronting the poppet valve. An annular lip projects obliquely from the seal is resiliently deformed by the poppet valve at the closed position, thereby cleaning debris off the sealing surface of the poppet valve.

Abstract: Disclosed is a pressure relief valve for attachment to a closed vessel having an opening to vent gas and liquids from the housing should the internal housing pressure rise to unacceptable levels. The pressure relief valve includes a single gasket that seals between a valve disk and a collar disposed about the opening. The gasket is fixed to the collar by a single retaining ring and effects seals with the disk valve in two planes, one seal is in a plane generally parallel to the plane of the opening and a second seal is in a plane generally normal to the plane of the opening. Moreover, the second seal remains in tact for a short time after the first seal is broken to permit the rapid separation of the disk valve from the gasket to vent gas and liquids from the housing.

Abstract: An inline check valve having a piston member and a seat in a valve body having a larger diameter at the end thereof away from the piston. The seat is retained within a groove by a seat retainer which prevents removal of the seat from the groove without deformation of the seat.

Abstract: A ball check valve including a housing and a ball element movably positioned in the housing. An insert member is located at an inlet port of the housing, and an elastomeric element is molded directly onto the insert member and is positioned facing toward an outlet port of the housing for engagement with the ball element. A ball seat is ground into the elastomeric element at a precise angle matching a tangential angle of contact with the ball element such that engagement of the ball element with the ball seat forms a seal preventing fluid flow from the outlet port through the inlet port.

Abstract: A volumetric pump for administering intravenous fluids to a patient comprises a housing having an elongate cavity therein with an open and a closed end. A resilient sheet of material having a centrally-located aperture covers the open end, and a pump shaft is slidably disposed through the aperture to form a sphincter seal therebetween. An inlet conduit leading from a fluid source (an IV bag) passes through the housing into the cavity near the open end thereof, and an outlet conduit leading to a fluid sink (the patient) passes through the housing from the cavity near the closed end thereof. The shaft is driven back and forth in reciprocating motion inwardly and outwardly of the cavity to produce, respectively, a positive pressure forcing fluid out of the outlet conduit to the fluid sink, and a negative pressure forcing fluid from the fluid source through the inlet conduit.

Abstract: A stop valve which is in particular constructed as a valve top for a sanitary fitting, contains an actuating member constructed as a rotary spindle. The actuating member, which is held in axially non-displaceable manner, engages with a hexagonal neck in a closing body, whose external thread engages in an internal thread of the valve top. The closing body has a closing face cooperating with a valve seat. The valve seat is displaceable to a limited extent in the axial direction and contains a rubber-elastic member.

Abstract: A valve having a valve body, a valve plug and a deformable valve seat. A generally annular, wedge-shaped space is provided between a portion of the valve seat and a seat support in the valve body. Closing the valve brings the valve plug into single line contact with the deformable seat. Continued closing creates a myriad of line contacts as the seat deforms into the wedge shaped space, occluding any foreign surface particles and bridging surface discontinuities.

Abstract: A valve seat for a ball valve of a positive displacement pump for producing fluid from a subsurface formation wherein the valve seat is provided by a valve assembly having a non-corrosive hollow metallic housing therein which may have an internal radial groove therein, the metallic housing having an elastomeric material forming a bonded insert which has an aperture therethrough and a chamfered face for seating the ball of the ball valve in sealing engagement with said bonded insert.

Abstract: Check valve apparatus for a fluid flow operates in response to a positive pressure of the fluid to move a spring biased diaphragm and valve element off its seat to allow the fluid to flow through the apparatus. When the pressure of the fluid flow drops, the valve is urged against its seat to provide a positive stop to the fluid flow. The valve apparatus includes a stem extending exteriorly of a housing in which the apparatus is disposed so that the valve may be manually opened by moving the valve off its seat to clear debris without contaminating the hands of the person working on the valve.

Abstract: A valve assembly which comprises an upper valve assembly and a lower valve assembly. The upper valve assembly includes a valve body, a spring retainer and an upper spring. The lower valve assembly includes a retainer ring, an O-ring and a valve seat member. The valve body comprises a valve disc and a valve stem. The valve disc has a lower peripheral surface which is bevelled, and the lower extremity of the bevelled surface meets an annular protrusion which has a flat lower surface. The O-ring fits within respective grooves provided in the retainer ring and the valve seat member. The valve seat is arranged to be located in a valve port, and when the upper valve assembly is moved downwardly the annular protrusion is forced against the O-ring which then forms an additional seal with the adjacent housing of the valve port to completely close the valve assembly.

Abstract: A sealing ring made up of nestable elements is constructed by forming a basic cylindrical-frustoconical element having the function of withdstanding the height variations which are liable to be produced by a force exerted on the sealing ring in its axis of revolution. At least one of the nestable elements is formed of expanded graphite and compressed with a constant ratio. The elements are then fitted within each other until a sealing ring of predetermined height is obtained.

Abstract: A valve seat for a valve used with a treater tank comprising a body having a generally cylindrical bore therethrough, the body having a first end, a second end and being made of metal, the first end having a counterbore concentric with the cylindrical bore, the body having means on the second end for mounting the valve seat in the valve and an insert carried by the body and received in the first end, the insert being comprised of an erosion-resistant synthetic polymeric material having a cylindrical passageway therethrough, the insert having a first portion defining first inner and outer concentric cylindrical surfaces, the first outer surface having a diameter greater than the diameter of the counterbore, an annular sealing surface being formed on the first portion, and a second, generally cylindrical portion, said second portion being received in the counterbore and means disposed between the body and the second portion to secure the insert to the body and effect fluid-tight sealing between said insert and

Abstract: The stepped borehole and the valve housing are normally provided with cylindrical circumferential sections, which have been subjected to fine finishing and which are in exact axial alignment with the borehole axis, O-rings being provided as sealing elements between these cylindrical circumferential sections. The production is expensive and requires a lot of work. The new connection is to be simpler from the point of view of production technology, easy to repair and easy to assemble. In order to achieve this, each sealing element (30, 30'), which is positioned within the tapped borehole (3, 3', 3", 3"') is a soft metal ring which has been cold-formed between the diametral step (15, 13) and a support surface of the housing under the influence of the thread tightening tension and which, due to its elasticity, compensates tolerances or inaccuracies resulting from the manufacturing process, ensures perfect sealing and contributes to a simplification of the manufacturing process and of the assembly operation.

Abstract: A high performance damper blade and damper blade seal combination including a damper blade having a planar portion perpendicular to the damper blade and a damper blade seal including a base and two upwardly extending legs. One leg of the damper blade seal contacts the damper blade body, while the other leg of the damper blade seal contacts the outside edge of the perpendicular tip portion of the damper blade. The tip of the perpendicular damper blade portion contacts the base of the damper blade seal for providing a third point of contact between the damper blade and the damper seal to ensure minimum airflow through the damper blade and end seal when the damper blade is in the closed position. Furthermore, the leg of the damper seal which contacts the outer side of the blade tip portion operates advantageously as a wind break to prevent leakage through the damper blade and seal combination due to wind gusts when the damper blade and seal are employed on air handler units or air conditioning systems.

Abstract: A solenoid operated flush valve has a main flush valve body including water inlet and outlet means. The main flush valve body includes generally horizontally extending nipple means which is in fluid communication with the water inlet and outlet means. A flow control means is removably mounted within the nipple means and includes valve insert means and solenoid means in cooperative engagement with the valve insert means. The valve insert means includes first and second ends and a side. The valve insert means includes a first passageway extending axially between the first and second ends thereof and a second passageway extending between one of the first and second ends and the side of the valve insert means. The second passageway is in fluid communication with the water outlet means through the side of the valve insert means. Means cooperate with the solenoid means for selectively blocking the second passageway to thereby regulate the flow of water flushing through the flush valve.

Abstract: In a check valve or stop/check valve comprising a housing having an inlet port, an outlet port and a valve seat between the two ports, a valve disc moves axially within a valve housing between open and closed positions, so that fluid flow applies pressure against the valve disc to automatically open the valve, but when the fluid stops or reverses, the valve automatically closes to prevent backwash. Under conditions of pulsating, low-volume fluid flow, a ridge on the valve seat and a deflector ring on the valve disc deflects the flow of fluid, thereby using the velocity of fluid to increase pressure against the valve disc so as to smoothly and gently move the valve disc, reduce vibration of the valve disc and prevent it from striking the valve seat.

Abstract: A valve employed in applications where the valve is rapidly cyclically opened and closed over extended periods of time is constructed in a manner such that the impact between a rapidly moving metal valve head and metal valve seat at valve closure is minimized to reduce noise and wear. The valve head engaging element of the valve seat may take the form of a frusto conical belleville washer located with its concave side resting on a flat planar wall surface in the valve housing or a flat washer bridging a frusto conical wall surface in the housing. Fluid filling the recess between the opposed surfaces of the washer and housing wall is expressed from the recess as the frusto conical washer is axially compressed against the wall by the closing valve head to further cushion or damp the resiliently resisted compression of the washer.

Abstract: A fluid flow control valve for a fixture having a conduit for the passage of a fluid through the fixture comprises a valve rod that is manually slideable through a hole in the fixture to intercept the conduit at right angles. The rod has a plurality of various apertures through the diameter, each alignable with the conduit and sealed of by an O-ring around the rod to prevent leakage along the rod. In addition, novel saddle shaped O-rings closely surrounding the conduit and conforming to the arcuate surface of the valve rod prevent peripheral leakage around the surface of the valve rod in its "off" position.

Abstract: A one-way pressure relief valve assembly is provided for venting the lubricant reservoir of a roller-type well drilling bit. The valve assembly is mounted in the cap of the lubricant reservoir, to open outwardly, and is adapted to provide hydrostatic loading of the valve element to its closed position.

Abstract: A packingless gate valve is disclosed which includes a housing having opposed similar housing halves with pipe nipples extending therefrom and with resilient sleeve units installed on respective lock rings mounted in recessed portions of the housing halves. The sleeves act to compressibly engage each other in the valve open condition and engage opposite sides of the gate in the valve closed condition. Each sleeve unit has a radially outwardly extending flange on the inner and outer axial ends with these flanges being located in indented regions between each lock ring and the respective housing half. An encircling thin stiffening ring of harder material is bonded to the axially outer surface of the flange on the inner end of each sleeve, each stiffening ring being shaped with a right angle bend so as to provide both axially and radially facing surfaces for each sleeve body. Each stiffening ring is engaged with the respective lock ring along the entire length of the stiffening ring.

Abstract: A gasket assembly including a base having a central opening and a circular slot having an undercut portion extending around the central opening, a circular gasket positioned in the circular slot and having a tapered side located proximate the undercut portion, and cementitious sealant material abutting the tapered side of the gasket and in the undercut portion for retaining the gasket in the slot. The gasket assembly is especially useful for the seal for the pressure relief valve of an electrical power transformer.

Abstract: A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping.