A valve for a displacement pump includes a valve body having an annular strikeface and defining an annular receptacle, and an annular seal received in the receptacle of the valve body, the seal including an annular contact surface, wherein the seal defines a cumulative displacement ratio of (i) at least one of at most 0.20 at a location that is spaced 40% from an inner diameter (ID) of the contact surface of the seal moving towards an outer diameter (OD) of the contact surface, (ii) at most 0.35 at a location that is spaced 55% from the ID of the contact surface moving towards the OD of the contact surface, and (iii) at most 0.45 at a location that is spaced 65% from the ID of the contact surface moving towards the OD of the contact surface.

A thin gas transportation device is provided and includes a shell, a check valve and a gas pump. The shell includes a shell surface, an accommodation slot and an outlet slot. The accommodation slot is recessed from the shell surface and includes an accommodation bottom surface. The outlet slot is recessed from the accommodation bottom surface. The check valve is disposed within the accommodation slot and includes a barrier plate and a valve plate. The barrier plate is disposed on the accommodation bottom surface and covers the outlet slot. The barrier plate includes a first surface, a second surface, a protruding part and a plurality of perforations. The protruding part is protruding from the second surface and located at the outlet slot. The valve plate is coupled to the second surface, and the protruding part abuts against the valve part and seals the valve hole.

A fluid flow control valve includes a valve body with a fluid flow lumen therethrough and a valve member located within the fluid flow lumen. At least one of the valve body and the valve member is resilient and respectively sized for movement between a normally closed position in which the valve member and a fluid lumen surface are in sufficient annular contact to block fluid flow through the fluid flow lumen and an open position in which at least one of the valve body and the valve member flexes to a spaced apart position that allows the fluid flow between the valve body and the valve member. Downstream fluid pressure may contact the valve body to enhance sealing. A fluid absorbent member may also be employed with the valve body. Flow control devices, such as medical fluid injection devices, and methods may employ the valve.

A fluid flow control valve includes a valve body with a fluid flow lumen therethrough and a valve member located within the fluid flow lumen. At least one of the valve body and valve member is resilient and respectively sized for movement between a normally closed position in which the valve member and a fluid lumen surface are in sufficient annular contact to block fluid flow through the fluid flow lumen and an open position in which at least one of the valve body and valve member flexes to a spaced apart position that allows fluid flow between them. Downstream fluid pressure may contact the valve body to enhance sealing. A fluid absorbent member may also be employed with the valve body. Flow control devices, such as medical fluid injection devices, and methods may employ this valve.

An air inflation device includes an inflation unit having a chamber in which air can be compressed to generate a high pressure air, and an air outlet channel communicating with the chamber. A pressure gauge unit includes a pressure gauge, a shaft extending outwardly from the pressure gauge and inserted into the air outlet channel, and a check valve sleeved on the shaft and movable between an open state for allowing the high pressure air in the chamber to flow into the air outlet channel, and a closed state for preventing the high pressure air in the air outlet channel to flow back into the chamber. An air guide unit is connected to the inflation unit for guiding the high pressure air to flow out of the air outlet channel.

A fluid flow control valve includes a valve body with a fluid flow lumen therethrough and a valve member located within the fluid flow lumen. At least one of the valve body and valve member is resilient and respectively sized for movement between a normally closed position in which the valve member and a fluid lumen surface are in sufficient annular contact to block fluid flow through the fluid flow lumen and an open position in which at least one of the valve body and valve member flexes to a spaced apart position that allows fluid flow between them. Downstream fluid pressure may contact the valve body to enhance sealing. A fluid absorbent member may also be employed with the valve body. Flow control devices, such as medical fluid injection devices, and methods may employ this valve.

In a piston pump, for example, a piston sub assembly includes a columnar plunger that lies along an axial direction, a cap that is fixed with the plunger to cover an adjacent region between a first end surface at one end in the axial direction of the plunger and the first end surface at a first outer circumferential surface of the plunger, and provided with an intake passage extending from an inlet on an outer side of the first outer circumferential surface to an outlet on an outer side of the first end surface outside the plunger, and a first valve seat of a first intake check valve located at the outlet, and a seal member that is a member different from the cap and that prevents leakage of hydraulic fluid from the first chamber through a gap between the first cylinder and the piston sub assembly.

A fluid control device includes a valve, a pump and a film valve. The valve includes a first main plate, a second main plate, a first side plate, and a valve chamber. The first main plate has a first vent hole, and the second main plate has a second vent hole. The film valve is disposed in the valve chamber. The first vent hole is positioned in a central region of the valve chamber, and the second vent hole is positioned in an outer end region of the valve chamber. The film valve is positioned between the first vent hole and the second vent hole. The film valve is fixed to the second main plate in a state in which an end portion on a side of the outer end region or an end portion on a side of the central region is capable of vibrating.

A pump (10) includes: a flat plate (20); a piezoelectric element (21); a flat plate (30); a side wall (40); a support member (22); a support member (32); a shielding plate (500); a ventilation hole (23); a ventilation hole (33); a film valve (61); and a film valve (62). The film valve (61) is arranged in a region where the flat plate (20) and the shielding plate (500) face each other. The film valve (62) is arranged in a region where the flat plate (30) and the shielding plate (500) face each other. A center side of one of the film valve (61) and the film valve (62) is fixed in a state in which an outer edge side is movable, and the outer edge side of the other is fixed in a state in which the center side is movable.

A pump includes a vibrating plate, a flow path forming member, a pump chamber, and a film valve. The vibrating plate is provided with a piezoelectric element, vibrates due to distortion of the piezoelectric element, and has a gap on an outer periphery. The flow path forming member is disposed so as to face the vibrating plate, and has a hole in a portion facing the vibrating plate. The pump chamber is surrounded by the vibrating plate and the flow path forming member, and has a central space communicating with the hole and an outer edge space communicating with the gap. The film valve is disposed in the pump chamber. The film valve is in contact with the vibrating plate and the flow path forming member when a pressure in the central space is lower than a pressure in the outer edge space.