Abstract: Welded check valves include a poppet assembly, a spring, and a disc that contacts the spring. The disc may be held at a position away from a weld when forming the welded check valve. Embodiments may include retention features configured to allow one or more of the poppet assembly and disc to pass the retention features in an assembly orientation, and to retain those elements when they are in an operational orientation. Methods include inserting the poppet assembly, contacting the poppet assembly with a spring, inserting a disc, retaining the disc away from a weld side, and welding the check valve together. The poppet assembly and/or disc may pass one or more retaining features when inserted, and be retained by the retaining features when the check valve is operated. The weld may be a thermal weld.

Abstract: Provided is a compressor including a valve unit including: at least two guide pins passing through a discharge valve; and through holes allowing the guide pins to pass therethrough to control oblique motion of the discharge valve with respect to a horizontal direction during up and down movement of the discharge valve. When the discharge valve obliquely moves up and down with respect to the horizontal direction, the guide pin comes into contact with at least two points of an inner circumferential surface of the through hole so that the oblique movement of the discharge valve is restricted, thereby improving the durability of the discharge valve and reducing noise during operation of the compression.

Abstract: An elastomeric component includes a body feature and a retaining feature coupled to the body feature. The retaining feature includes an insertion end portion, and a retention end portion spaced apart from the insertion end portion along a longitudinal axis. The insertion end portion defines a catch spaced apart from the retention end portion and having a contact location adapted to make first contact with an edge of a retaining hole. The contact location is spaced apart from the catch a first distance. The retaining feature has a blind pocket extending from the retention end portion interiorly of the retaining feature along the longitudinal axis. The blind pocket terminates at an end location spaced from the catch. The elastomeric component may be coupled to a wall defining the retaining hole. Methods of assembly, and an apparatus for installation, are also provided.

Abstract: A multi-compartment transport refrigeration system includes a heat rejecting heat exchanger downstream of a compressor discharge port; a first evaporator expansion device downstream of the heat rejecting heat exchanger; a first evaporator having an first evaporator inlet coupled to the first evaporator expansion device and a first evaporator outlet coupled to the compressor inlet path, the first evaporator for cooling a first compartment; a second evaporator expansion device downstream of the heat rejecting heat exchanger; a second evaporator having a second evaporator inlet coupled to the second evaporator expansion device and a second evaporator outlet coupled to the compressor inlet path, the second evaporator for cooling a second compartment; and a first evaporator outlet isolation valve positioned in an outlet of the first evaporator, the first evaporator outlet isolation valve to prevent migration of refrigerant from the second evaporator outlet to the first evaporator outlet.

Abstract: A piston-type fuel pump for an internal combustion engine includes a pump housing, a piston, an annular counterplate, and a non-return outlet valve. The pump housing includes a stepped opening and a piston opening. The piston is guided in the piston opening. The counterplate is pressed into the stepped opening and includes a valve seat. The non-return valve includes a valve element and a guide element. The guide element guides the valve element, is arranged radially outside the valve element and in the stepped opening, and includes a guide section, a retention section, and a support section. The guide section guides the valve element, the retention section is connected to the guide section via a radially extending connecting section, and the support section supports a valve spring. The sections are arranged axially at different points such that the guide section is between the counterplate and the support section.

Abstract: The multi-stage submersible pump at the exit side is provided with a non-return valve (9) including a valve seat (19) and a shut-off body (15) which is movably arranged thereto in a limited manner and which is arranged with a positive fit and in a movable manner within a guide (16) surrounding the shut-off body (15) with play. The inner contour of the guide (16) tapers inwards towards the valve seat (19), counter to the main flow direction (13).

Abstract: A sanitary automatic glove dispensing apparatus and method of use. The automatic sanitary glove dispensing apparatus, based on one or more received dispensing events, dispenses pairs of connected protective gloves stored on a roll of protective gloves and overlapped in a pre-determined pattern, by both cuff ends so both finger ends of the protective gloves are not contaminated during dispensing. After a pair of protective gloves are dispensed by both cuff ends, no additional protective gloves are exposed from the apparatus until another protective glove dispensing event is received, thereby protecting remaining protective gloves in the apparatus from contamination by noroviruses and bacteria from a surrounding environment and from other users of the apparatus.

Abstract: An odor-trap device (1) for in particular flushing-water-free sanitary devices, for example urinals, comprises an outflow element (2) with a sealing wall (3), and also comprises a sealing membrane (4), which is in sealing contact with the sealing wall (3) in a closure position and, in the presence of a liquid, such as urine, is pushed away from the sealing wall (3) from the closure position into an open position, as a result of which a gap (19) is formed between the sealing membrane (4) and sealing wall (3), it being possible for the liquid to be led away through said gap, and further comprises a mounting element (5) for mounting the sealing membrane (4) in relation to the sealing wall (3).

Abstract: A valve member assembly includes a housing, a check valve assembly, and a float valve assembly. The housing is a cup, a retainer and a bonnet releasably secured together. The check valve assembly is positioned within the cup, and the float valve assembly is positioned between the bonnet and the retainer. The valve member assembly can be easily assembled and inserted into a valve body.

Abstract: Disclosed is a one-way valve characterized as a new form of check valve wherein an affixed free moving film device, downstream edge control techniques, a channel surface and the motive force of directional pressurized fluid flows cooperatively permit forward fluid flow yet check reverse fluid backflow through the valve assemblage to achieve a unidirectional flow.

Abstract: A valve assembly (10) is to be used in conjunction with a tubular member having an internal surface surrounding a passage into which the valve assembly is to be sealingly inserted. The valve assembly includes a tubular body (25) having a longitudinal passage and an outer surface to be located adjacent the internal surface. A seal (29) is mounted on the outer surface to engage the internal surface to sealingly connect the tubular body with the tubular member. A movable valve member (33) is movable between an open position providing for the flow of water from an upstream end to a downstream end of the passage of the tubular body and a closed position closing the passage. Resilient means, such as a spring (34) urges the valve member to the closed position. The resilient means is configured to provide for displacement of the valve member toward the open position when pressure beyond a predetermined pressure is applied upon the movable valve member.

Abstract: An improved valve assembly having an integral single piece housing (1) having an inlet (15), an outlet and defining an inwardly extending wall forming a valve seat (3); a valve member (4) moveable within the housing (1) between a closed position and an open position and a seal (11) to form a fluid tight seal between the valve member (4) and the valve seat (3) when the valve member is in the closed position. The seal (11) also acting to retain the valve member (4) within the housing (1) and in which the housing defining end portions which extend axially away from the valve member (4) at any position of the valve member between the open and closed positions.

Abstract: A backflow prevention assembly is disclosed including a backflow prevention valve having a valve housing including a valve inlet end and a valve outlet end; a spool spacer of predetermined length having a first end and a second end; an inlet shut-off valve; and an outlet shut-off valve, wherein the spool spacer extends between the backflow prevention valve and one of the inlet shut-off valve and the outlet shut-off valve. The entire assembly, including the backflow prevention valve, the spool spacer, the inlet shut-off valve, and the outlet shut-off valve, is a certified assembly, certified by a certifying authority prior to installation. Methods of manufacturing a backflow prevention assembly and replacing a backflow prevention assembly are also disclosed.

Abstract: A pouch air valve used on a sealing pouch comprises a coupling duct and a piercing base. The coupling duct includes a duct, an air valve and a first suction plate. The piercing base has a piercing head and a second suction plate. The first suction plate surrounds and seals the duct to form coupling therewith. The piercing head has an airflow passage running through two sides thereof. The second suction plate surrounds and seals the piercing head to form coupling therewith. The piercing base is positioned at one side of the sealing pouch while the duct is directly aligned and coupled with the piercing head from another side of the sealing pouch so that the piercing head can pierce through the sealing pouch to allow the first and second suction plates to attract each other and anchor on the sealing pouch which serves as separation.

Abstract: A device suitable for retrofitting in laid pipelines is intended to be able to be placed and fixed in place in the pipeline. Transport of the device to the installation location is intended to be performed using as little force as necessary, and the sealing element is intended to be displaced without contact and thus without wear. To this end, the device, in the interior of which a shut-off device (6) is disposed, is designed so that an offset, conically tapering region (10) is adjacent to a front cylindrical region (3) and is bounded by a stop collar (12) on which a connecting contour (7) for a coupling piece of a drive element is connected. A sliding piece (13) made of an expandable material is displaceably disposed in the axial direction on the conically tapering region (10), comprising a circumferential groove in which a spring-loaded clamping ring (15) is supported.

Abstract: A check valve system including a plumbing assembly and a check valve assembly. The plumbing assembly has at least three portals including a first portal, a second portal and a third portal. The check valve assembly is positioned to block a fluid flow entering the second portal from flowing out of the first portal. The check valve assembly includes a securing mechanism positioned in the third portal.

Abstract: The invention relates to a one-piece plastic element having an inlet valve cover and an inlet valve seat element for an inlet valve of a piston pump of a hydraulic brake system of a motor vehicle. The inlet valve is designed as a check valve, and the inlet valve cover and the inlet valve seat element are connected to each other by a designed fracture point. The invention further relates to a piston pump having an inlet valve cover and inlet valve seat element made of a one-piece plastic element. The invention further relates to a method for assembling the inlet valve designed as a check valve.

Abstract: One embodiment relates to an automatic fluid flow control device 1 for a fluid supply, the device comprising: an actuator 41 that carries or includes a magnet 43, the actuator being movable within a housing 3 from a first position corresponding to a normal fluid supply to a second position corresponding to a fluid oversupply, wherein the actuator 41 is removable from the housing 3 to enable the device to be cleaned, and the housing and actuator are configured so that the actuator can only be accommodated in the housing in an orientation that enables the magnet to exert a magnetic force to close a valve in the fluid supply as the actuator moves from the first to the second position.

Abstract: A pump has a pump fluid end and a manifold that is detachable from the fluid end. A device is attachable to the pump, and has a manifold support beam portion adapted to affix to the pump fluid end at a location adjacent a manifold mating surface of the pump fluid end and extend outward from the pump fluid end. A support is provided on the manifold support beam portion that, when the manifold support beam portion is affixed to the fluid end of the pump, engages the manifold detached from the fluid end and supports the weight of the manifold.

Abstract: A vacuum relief valve is provided. The vacuum relief valve includes a body having a side wall, and a stem that is movable with respect to the body between an open position and a closed position. The stem is biased in the closed position. The vacuum relief valve further includes a first sight glass coupled to the body and configured to enable visual inspection of a sealing area of the vacuum relief valve. The sealing area includes at least a portion of said stem.

Abstract: A piston compressor, particularly a refrigerant compressor includes a compression chamber in a compressor block, the compression chamber being delimited by a cylinder head (10), the cylinder head (10) comprising at least one valve plate arrangement with at least one suction valve (23, 24) and at least one pressure valve (21, 22), as well as a valve cover (12). To achieve low manufacturing costs, though maintaining a good efficiency, the valve plate arrangement (16) is formed by a carrier plate (17) that comprises the suction valve (23, 24, 26, 27) and the pressure valve (18, 19, 21, 22) and is connected by at least one gas-tight connection seam (28, 31) to the valve cover (12), the connection seam (28, 31) separating a suction area (32) and a pressure area (29, 30) from one another and sealing at least the pressure area (29, 30) towards the outside.

Abstract: The disclosure relates to a safety device to be inserted in a pipe through which a fluid flows from an upstream side to a downstream side, this device comprising a tube offering the fluid a central flow path controlled by a central valve which closes in the event of excessive flow of this fluid, an elastically deformable annular shutter mounted on the external periphery of the tube, and retention clamps. According to the disclosure, each of the clamps has a tied end fastened to the periphery of the tube upstream of the annular shutter and can adopt, under the effect of a radial compression, a folded configuration in which its free end is turned towards this annular shutter.

Abstract: A poppet-style check valve for allowing uni-directional flow in a fluid conducting system. The check valve comprises a valve body, and a poppet mounted therein for reciprocal axial movement between a first position in which the poppet is pressed against a valve seat restricting flow through the check valve, and a second position in which the poppet is spaced from the valve seat permitting flow through the check valve. An inner bore of the valve body is expanded in the area of the poppet to maximize flow through the check valve, and the external dimensions of the check valve are minimized by eliminating a conventional liner between the poppet and the valve body. Additionally, the elements of the valve mechanism are designed such that they lock in place within the valve body during assembly.

Abstract: A device for the protection against the rupture of pipes carrying a fluid includes two or more flow channels and a closing element which interrupts the flow of fluid if a predetermined permissible volume flow is exceeded. At least one of the flow channels can be closed by a test closure in order to increase the flow speed in the remaining flow channels and for test purposes to bring about a movement of the closing element into the closing position. In this way, devices for the protection against the rupture of pipes integrated into complex systems carrying a fluid can be tested in situ to verify their proper functioning.

Abstract: A retainer for movably securing a valve member within a fluid bore of a pump comprises a retainer head which includes at least one peripheral groove and a retainer hub which is connected to or formed integrally with the retainer head. The valve member is movably coupled to the retainer hub, and the retainer head is movable to position the groove over a radial protrusion in the fluid bore. In this position, the retainer is secured to the pump and the valve member is accordingly movably secured within the fluid bore.

Abstract: A fluid flow controlling system for controlling the flow of fluid from a tank having an exterior surface is provided. The system includes an angle valve and a check valve. The angle valve is coupled to the tank and located substantially on an outer side of the exterior surface. The angle valve includes a spindle, a valve seat and a valve seal. The spindle, valve seat and valve seal are located on an inner side of the exterior surface. The check valve is coupled to the tank and located substantially on the inner side of the exterior surface. The check valve is movable between a closed state and an open state by the spindle.

Abstract: A backflow preventer that generally includes a modular fluid arrangement having a modular strut, a one-piece modular cage, a relief valve fluidly connected to the modular cage, and at least one in-line check valve removably housed in the modular cage. In operation, when backflow occurs, pressure in a chamber of the relief valve increases to provide a passageway for fluid to flow out of the modular cage, through the relief valve, to the environment. When the backflow stops, the pressure in the chamber decreases and the passageway closes, moving the fluid through the interior of the modular cage.

Abstract: A backwater valve assembly includes a valve housing, a valve member and a servicing tool. The valve housing has an internal ledge within its interior on which is positioned a retainer clip oriented in vertical alignment with a riser. The valve member has a first engagement of a two part engagement on one face and a mounting along a peripheral edge which includes transverse pins adapted to engage the retainer clip. The servicing tool includes a second engagement of the two part engagement at a working end of a shaft. The hook engages the hook receiver of the valve member during insertion and removal.

Abstract: A retainer for movably securing a valve member within a fluid bore of a pump comprises a retainer head which includes at least one peripheral groove and a retainer hub which is connected to or formed integrally with the retainer head. The valve member is movably coupled to the retainer hub, and the retainer head is movable to position the groove over a radial protrusion in the fluid bore. In this position, the retainer is secured to the pump and the valve member is accordingly movably secured within the fluid bore.

Abstract: The invention relates to a valve which is insertable into a receiving recess (21) of a valve carrier (22), the valve (1, 1?) comprising a first housing part (2, 2?) and a closing body (4). The closing body (4) cooperates with a sealing surface (9) to form a sealing seat, the valve (1, 1?) being fixable in the receiving recess (21) of the valve carrier (22) by means of the first housing part (2, 2?). A second housing part (3, 3?) is connectable by way of a first end (7) to the first housing part (2, 2?) and the sealing surface (9) cooperating with the closing body (4) is formed on the second housing part (3, 3?).

Abstract: A projecting connecting portion 32 which is fitted to a socket S10 and a valve seat 33 are provided in a plug main body 31 of a plug P10. The valve main body 31 having a valve head 35 which is urged to the valve seat 33 for sealing is provided in the plug main body 31 and the projecting connecting portion 32. Breaking starting portions 71 and 72 are provided in at least a part of the projecting connecting portion 32 and/or the valve stem 35b. A position at which breaking occurs when an excessive force exceeding a normal range of use is applied is set at a predetermined position whereby, when breakage occurs, the sealed state between the valve seat 33 and the valve head 35a can be maintained.

Abstract: A top entry in-line repairable swing check valve having a valve body adapted for connection within a flow-line and having flow passages and a valve chamber and further defining a seat recess at the juncture of a flow passage and the valve chamber. A removable seat assembly within the seat recess establishes sealing with the valve body. A swing check member is pivotal within the valve chamber between an open position permitting flow through the flow passages and a closed position in sealing engagement with the seat assembly. The valve body has an access opening to the valve chamber of sufficient dimension for movement of the seat assembly and the swing check member therethrough. A bonnet closure for the access opening supports seat retainer pins positioned in seat retaining relation with the seat assembly. A bonnet orienting pin projects from the valve body and is received by an orienting hole of the bonnet to align the bonnet and seat retainer pins with respect to the valve body.

Abstract: The present invention provides a method and apparatus for using hot gas to defrost sequentially each refrigerated display case (evaporator) in a group of refrigerated display cases (evaporators). A unique cross-feed line connects the distributor and the evaporator suction line for each evaporator in the group of evaporators. Like a typical hot gas defrost system, the sequential hot gas defrost system may be time-initiated and time-terminated or time-initiated and temperature-terminated. Each evaporator in the group of evaporators is defrosted in turn while the remaining evaporators in the group continue to operate in the refrigeration mode. A unitary combination check valve and orifice simplifies the sequential hot gas defrost refrigeration system.

Abstract: Disclosed is a check valve (5) that is screwed into a threaded bore (1) of a housing (2) of a hydraulic subassembly between a first pressure side (26) and a second pressure side (27) by means of an external thread (11) which is disposed in a first cylinder section (8) of a cylindrical valve housing (6) of the check valve (5). A passage duct (39) which allows a hydraulic fluid to flow between the sidewall of the threaded bore (1) and a first removed portion (16) of the surface area (10) of the cylindrical valve housing (6) is embodied in at least one angular segment (a1, a2, and a3) of the valve housing (6).

Abstract: The invention relates to a method of setting the ball travel of a valve-closing body, designed as valve ball, of a control valve of a hydraulic valve-lash-adjusting element which has a plunger with a plunger head and a central bore, a valve seat being provided at the outer end of this central bore, this valve seat being controlled by a valve ball, the ball travel of which is limited by a valve cap which has a cap flange and a cap base, the cap flange resting with its bearing surface on a base of a recess of the plunger head, and a stop of the cap base serving as a travel limit for the valve ball.

Abstract: Apparatus and methods for constructing a valve comprising a sealing member and a hollow ball operable to sealingly engage the sealing member. A guide housing disposed about said hollow ball and does not constrain rotation of said hollow ball. A spring is disposed between the hollow ball and the guide housing so as to bias the hollow ball into sealing engagement with the sealing member. The hollow ball is constructed from two unequal sized portions and may comprise a hollow, spherical body having an aperture and a plug sized so as to closely fit within the aperture.

Abstract: A safety relief valve is provided that comprises a body comprising a chamber therein and an inlet and an outlet, the inlet comprising an inlet valve seat; a disk member closeable on the inlet valve seat; and a mechanism in the body biasing the disk member to rest on the inlet valve seat with a set force such that when the pressure in the inlet exceeds a set pressure resulting from the set force, the disk member is lifted from the inlet valve seat, the mechanism comprising a combination of a coil spring and one or more disk springs stacked in series with the coil spring. A method of preparing a coil spring for use in a pressure relief valve comprises measuring the spring rate of the coil spring and; modifying the spring so as to modify its spring rate to be within ±2% of a desired spring rate.

Abstract: A valve apparatus is small, and regulates a fuel amount by restricting a lift amount of a valve. A columnar portion is formed on a pump body. The columnar portion is inserted into a check valve and a washer formed with a protruding portion which protrudes outward from a flange portion, and the check valve and washer are attached or fixed to the pump body by subjecting a tip end of the columnar portion to thermal caulking or the like. An outer diameter of the protruding portion is set to be relatively smaller than an outer diameter of the flange portion such that when the check valve is sandwiched between the protruding portion and pump body, the check valve contacts an outer peripheral edge of the flange portion when the check valve opens. As a result, a lift amount of the valve can be restricted, and a flow rate of fuel passing through a passage can be maintained at a constant level.

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: Embedded check-valve manufacturing assembly (100, 600) for subsequent firing and integration in a micro-fluidic system. The assembly can include a check-valve chamber (104, 604), an inlet port (106, 606) and an outlet port (108, 608) formed from at least one layer of an unfired low-temperature co-fired ceramic (LTCC) tape to form a substrate (102, 602). A plug (114, 614) is disposed within the check-valve chamber that is capable of withstanding the LTCC firing process without damage or distortion.

Abstract: Embedded check-valve manufacturing assembly (100, 600) for integration in a micro-fluidic system. The assembly can include a check-valve chamber (104, 604), an inlet port (106, 606) and an outlet port (108, 608) formed from at least one layer of an low-temperature co-fired ceramic (LTCC) tape to form a substrate (102, 602). A fired LTCC plug (114, 614) is disposed within the check-valve chamber.

Abstract: A pressure relief valve (10) includes a housing (20) defining an air flow passage (34). A flap (90) overlies the air flow passage (34). At least a portion (92, 94) of the flap (90) is movable, in response to an air pressure differential acting on opposite portions of the flap, between an open condition venting air from one side (18) of the valve (10) to a closed condition blocking flow of air from a second side (19) of the valve. The flap (90) has a plurality of mounting openings (104, 106). The housing (20) has a plurality of generally T-shaped mounting posts (70, 72) projecting from the housing. A snap connection is provided between the flap (90) and the mounting posts (70, 72) to secure the flap to the housing (20) with the mounting posts extending through the openings (104, 106). The mounting posts (70, 72) are the only structure holding the flap (90) on the housing (20).

Abstract: A fluid spray apparatus with a controlled supply of pressurized fluid delivered through a network of tubes to a spray head having a plurality of stop flow valves and nozzles that will automatically shut off the flow of fluid out of the nozzles when the pressure of the fluid drops below a threshold level. The spray head preferably has a central chamber that is open to the stop flow valves and dampens any fluctuations in pressure and volume of fluid from the source of pressurized fluid. The nozzle is preferably mounted to the stop flow valve. The stop flow valve has a biased valve head that engages a seat until the pressure exerted on the valve head by the fluid exceeds a threshold level and the valve opens. One embodiment has a quick connect coupling with a base, seal and collar that will allow spray heads of various numbers of nozzles to be quickly exchanged. Another embodiment is adapted to couple with a conventional paint spray compressor and gun.

Abstract: Embedded check-valve assembly (100, 600) for integration in a micro-fluidic system. The assembly can include a check-valve chamber (104, 604), an inlet port (106, 606) and an outlet port (108, 608) formed from at least one layer of liquid crystal polymer (LCP) film to form a substrate (102, 602). A plug (114, 614) is disposed within the check-valve chamber.

Abstract: Check valves including components having a straightforward and simple design allowing the components to be scaled down to an extremely small size without losing functionality or performance of the check valve.

Abstract: A Vacuum Relief Assembly for I.C. Engine Intakes is disclosed. Also disclosed is a device that permits outside air into the intake tract of an internal combustion engine in the event of an excessively high vacuum condition within the intake tract. Furthermore, the device is constructed from durable materials and resists the excessive temperatures found in the engine compartment of a vehicle. Still further, the device is made from two half-cylindrical sections that mate to one another around the intake tract to form a cylindrical attachment. The method of installation enables the device to be installable onto the intake tract in situ, and without the need to cut out a section of the tract.

Abstract: An integrated in-line tube and check valve assembly fabricated by end-form mandrel expanding an outlet end portion of deformable tube stock, such as metal, of nominal starting diameter, and concurrently end-forming a valve seat on the inside of the expanded tube section where it necks down and integrally joins the upstream nominal diameter portion of the tube. A valve ball and a valve spring are then fitted into the expanded tube section, together with a spring holder if needed. The expanded end portion of the tube is then again deformed by an end-form swaging operation that reduces the diameter of the expanded tube outlet end so as to form a cavity within the tube in which the spring is captured in compression for resiliently biasing the valve ball against the valve seat.

Abstract: A check valve for use in a section of a liquid flow line to control the intermittent flow of a liquid through the line, wherein the section of the line that is configured to received the valve has inlet and outlet ends with an opening through which liquid respectively enters or exits the section, includes a compression spring having upstream and downstream ends, wherein the spring is configured so as to allow the downstream end to press against the section outlet end. This check valve further includes a piston having bottom, top and outer side surfaces, with this piston having a cavity that extends from its top surface and is configured to allow the spring to sit and operated freely within the cavity with the spring's upstream end resting on the bottom surface of the cavity.

Abstract: A back flow prevention device is shown for use in a plastic pipeline for conveying water, sewage, hydrocarbons or other fluids. A valve body features a flow control mechanism which is formed entirely or primarily of plastic materials. The valve body and its opposing ends are formed of a plastic material which is compatible with the plastic material of the existing pipeline, whereby the valve body can be installed in the pipeline in co-axially fashion by directly joining the opposing ends of the body to the opposing mating pipe ends at a selected location within the pipeline.

Abstract: A suction valve coupling structure for a reciprocating compressor is disclosed in which a piston being linearly moved in a cylinder upon receipt of driving force from an electric mechanism unit, according to which gas flows through a gas flow passage formed therein, is coupled by welding to a valve for opening and closing the gas flow passage, thereby strengthening the coupling state of the suction valve. Since the coupling structure is simplified, a dead volume is reduced and a stroke volume is increased, improving compression efficiency. A stroke control of the piston is facilitated to enable a precise control of movement of the piston. In addition, a reliability of the coupling of the suction valve can be improved.