An annular groove has: a side peripheral surface that is shaped in a ring form and is formed such that the side peripheral surface inwardly extends from a bottom surface of the annular groove in a radial direction of a tubular member and is joined to an inner peripheral wall of the tubular member; and a specific shape surface that is formed along at least a part of the side peripheral surface between a bottom surface side end part and an inner peripheral wall side end part of the side peripheral surface such that a diameter of the specific shape surface is progressively reduced in an axial direction of the tubular member from one axial side, at which the bottom surface is placed, toward another axial side, at which the inner peripheral wall is placed.

Check valves include a valve seat and a movable valve member, or piston. Movement of the piston is what allows fluid to either flow or be prevented from flowing. A magnetic check valve is provided that contains an annular piston, which is configured such that the fluid flows through a central aperture in the piston. Fuel cell systems include a cathode loop which is in contact with the proton exchange membrane (PEM). The PEM is sensitive to fowling by contaminants that may be present in the ambient air. The magnetic check valve apparatus disclosed herein prevents backflow of air through the exhaust side of the cathode loop. The valve is used on the inlet side of the cathode as well.

An automatic ring valve 10 comprising a valve seat 12 provided with a plurality of gas flow passages 14 arranged according to at least one annular row, at least a shutter 18 comprising at least one ring-shaped portion for selectively closing and opening the gas flow passages 14, wherein said ring-shaped portion of the shutter 18 comprises a fiber-reinforced matrix 40, at least one contrasting member for contrasting an opening movement of ring-shaped portion of the shutter 18, wherein said ring-shaped portion of the shutter 18 comprises a structural core 18A made by said fiber-reinforced matrix 40, and wherein at least a portion of said structural core 18A is covered by at least one primary layer 18B, designed to improve fracture and/or impact and/or wear resistance of said ring-shaped portion.

An automatic ring valve 10 comprising a valve seat 12 provided with a plurality of gas flow passages 14 arranged according to at least one annular row, at least a shutter 18 comprising at least one ring-shaped portion for selectively closing and opening the gas flow passages 14, wherein said ring-shaped portion of the shutter 18 comprises a fiber-reinforced matrix 40, at least one contrasting member for contrasting an opening movement of ring-shaped portion of the shutter 18, wherein said ring-shaped portion of the shutter 18 comprises a structural core 18A made by said fiber-reinforced matrix 40, and wherein at least a portion of said structural core 18A is covered by at least one primary layer 18B, designed to improve fracture and/or impact and/or wear resistance of said ring-shaped portion.

Disclosed is a fluid unidirectional flow structure. The fluid unidirectional flow structure (100) comprises; a first flow-checking body (110) and a second flow-checking body (120); the first flow-checking body (110) comprises a first connection portion (111) that is interconnected with a first flow portion (112) having at least one first through-hole (113); the second flow-checking body (120) comprises a second connection portion (121) interconnected with a second flow portion (122) having at least one second through-hole (123); when a fluid reverses directions, at least part of the first flow portion (112) moves relative to at least part of the second flow portion (122). The fluid unidirectional flow structure (100) may be designed in any shape, so as to facilitate installation. Also disclosed are a check assembly, and a respiratory device, when used on a breathing passageway, the invention may be adapted to a respiratory passageway of any size and shape. The fluid unidirectional flow structure (100) may also be installed on the body of a respiratory isolation mask (1000), wherein the shape of said mask may be adapted to the shape of the face of a person or animal. The shape of the first flow-checking body (110) and of the second flow-checking body (120) may be configured to be adaptable, so as to better bring into play the function and utility of the fluid unidirectional flow structure.

A thermodynamic valve for retaining vapours and gases and relieving pressure and vacuum for use in the venting of tanks or reservoirs of combustible liquids (fluids), said valve comprising: upper diaphragm ring (3a) and lower diaphragm ring (3b) that act through the thermodynamic action of the positive and negative pressures inside positive pressure (4) and negative pressure (5) chambers fixed to one another, a cap (2) screwed on the body of positive pressure chamber (4) and having upwardly directed lateral openings and a rupture seal (1) fitted in the upper section of cap (2). A base (5.1) with an inner fire-break fabric (6) is positioned on the inner lower section of negative pressure chamber (5) and connected to the fuel tank venting pipe.

A thermodynamic valve for retaining vapours and gases and relieving pressure and vacuum for use in the venting of tanks or reservoirs of combustible liquids (fluids), said valve comprising: upper diaphragm ring (3a) and lower diaphragm ring (3b) that act through the thermodynamic action of the positive and negative pressures inside positive pressure (4) and negative pressure (5) chambers fixed to one another, a cap (2) screwed on the body of positive pressure chamber (4) and having upwardly directed lateral openings and a rupture seal (1) fitted in the upper section of cap (2). A base (5.1) with an inner fire-break fabric (6) is positioned on the inner lower section of negative pressure chamber (5) and connected to the fuel tank venting pipe.

A reciprocating gas compressor valve having a plurality of clusters of kidney shaped holes positioned along a common circular or annular locus in the main body and a sealing element with a top portion, a bottom portion and a tubular section. The tubular section is integrally connected to the top portion and bottom portion. In an open position, a flow pathway is provided through the clusters of kidney shaped holes and the tubular section and the bottom profile abuts a stop surface of the valve. In a closed position, the top profile abuts the seat for sealing gas flow within the valve.

A reciprocating gas compressor valve having a plurality of clusters of kidney shaped holes positioned along a common circular or annular locus in the main body and a sealing element with a top portion, a bottom portion and a tubular section. The tubular section is integrally connected to the top portion and bottom portion. In an open position, a flow pathway is provided through the clusters of kidney shaped holes and the tubular section and the bottom profile abuts a stop surface of the valve. In a closed position, the top profile abuts the seat for sealing gas flow within the valve.

Check valve assembly (1, 1′) for a shock absorber (100) comprising a housing (10). The housing (10) comprises a first volume (11), wherein a pressure P1 prevails; a second volume (12), wherein a pressure P2 prevails; a first housing portion (VE1), and a second housing portion (VE2). The housing (10) further comprises a fluid passage (20) between said first (11) volume and said second (12) volume; and a spool (40), said spool (40) being movably arranged in said housing (10) between at least a first position in which a flow of fluid through said fluid passage (20) between the first (11) and second (12) volume is allowed and at least a second position in which a flow of fluid through said fluid passage (20) between the first (11) and second (12) volume is prevented. The spool (40) comprises a first portion (S1) adapted to engage with said first portion (VE1) of said valve housing 10, forming a first region of engagement (RE1), and a second portion (S2) adapted to engage with said second portion (VE2) of said valve housing (10), forming a second region of engagement (RE2). Further, the first region of engagement (RE1) is arranged at a first location and said second region (RE2) is arranged at a second location. Also, a shock absorber (100) comprising a working cylinder (C) adapted to receive a working fluid, a piston dividing said cylinder (C) into a first (WC1) and a second (WC2) working chamber and a check valve assembly (1, 1′) according to above. Further, a front fork comprising such a check valve assembly (1, 1′).