A one-piece flap valve (150) comprising first and second portions hingedly connected to one another by a flexible strip, the first portion having a hingeable internal valve flap (152) and the second portion comprising an at least partially annular valve seat (154). The first and second portions being socket-fitted together by relative movement, such that the valve seat (54, 154) is spanned by the flap (152), the second portion comprising first and second legs (121a, 121b) having first and second locking lugs (127a, 127b) extending radially outwardly therefrom, the locking lugs for location within locking apertures (125a, 125b) of a tube body (10) of a dispenser. The flap valve (150) comprising a retaining mechanism configured and arranged such that once the flap valve is installed in a tube body of a dispenser, the retaining mechanism resists against radially inward displacement of the first and second legs.

An air stop sheet of a piston of a cylinder, the piston is accommodated in a compressor, and an air stop sheet is accommodated on a head of the piston. The air stop sheet includes a bending section having a positioning zone and an acting zone. The bending section is a boundary line of the acting zone and the positioning zone so that a positive surface of the air stop sheet forms an obtuse angle less than 180 degrees, and a back surface of the acting zone of the air stop sheet backing the top of the cylinder turns on relative to the plane of the top of the head at an open angle θ, thus producing an air flowing space. A piston rod extends downward from the head and includes an air conduit communicating with the air channel.

One or more techniques and/or systems are disclosed for a flap valve in a diaphragm pump. The flap valve includes a body and a self-centering hinge portion. A front portion of the body includes a front surface having a raised portion and a recessed portion. The front surface is configured to form a seal with a surface of the pump when the body is in a closed position, the surface of the pump being at an inlet or an outlet of a pumping chamber. The body is configured to allow a downstream flow of a fluid when the flap valve is in an open position. The self-centering hinge portion is operably connected to the body. The self-centering hinge portion has a dynamically changing longitudinal axis. The body is configured to simultaneously translate and rotate about the dynamically changing longitudinal axis to form the seal.

A one-piece flap valve (150) comprising first and second portions hingedly connected to one another by a flexible strip, the first portion having a hingeable internal valve flap (152) and the second portion comprising an at least partially annular valve seat (154). The first and second portions being socket-fitted together by relative movement, such that the valve seat (54, 154) is spanned by the flap (152), the second portion comprising first and second legs (121a, 121b) having first and second locking lugs (127a, 127b) extending radially outwardly therefrom, the locking lugs for location within locking apertures (125a, 125b) of a tube body (10) of a dispenser. The flap valve (150) comprising a retaining mechanism configured and arranged such that once the flap valve is installed in a tube body of a dispenser, the retaining mechanism resists against radially inward displacement of the first and second legs.

One or more techniques and/or systems are disclosed for a flap valve in a diaphragm pump. The flap valve includes a body and a self-centering hinge portion. A front portion of the body includes a front surface having a raised portion and a recessed portion. The front surface is configured to form a seal with a surface of the pump when the body is in a closed position, the surface of the pump being at an inlet or an outlet of a pumping chamber. The body is configured to allow a downstream flow of a fluid when the flap valve is in an open position. The self-centering hinge portion is operably connected to the body. The self-centering hinge portion has a dynamically changing longitudinal axis. The body is configured to simultaneously translate and rotate about the dynamically changing longitudinal axis to form the seal.

A valve clack is provided. The valve clack includes: a mounting column (11) having a plurality of air slots (111) for dispersing an airflow at least in a top surface of the mounting column (11); a plurality of blades (12) arranged outside the mounting column (11) in a circumferential direction of the mounting column (11), each blade (12) having a radial inner end connected to the mounting column (11) and elastically swingable with respect to the mounting column (11).

An air pump is provided. An air pump includes an upper cover, a valve seat, a spacer, an air intake one-way valve and a piston assembly. The upper cover has an air outlet. The valve seat is disposed on a bottom of the upper cover. The spacer is disposed between the valve seat and the upper cover and has an air intake chamber and an air outtake chamber. The air intake chamber has an air intake passage communicated therewith, and the air outtake chamber having an air outtake passage communicated therewith. The spacer has a valve clack, so that air flows in a one-way direction from bottom to top. The air intake one-way valve is disposed and movable in the air intake passage so as to make the air flow in the one-way direction from top to bottom. The piston assembly is disposed under the valve seat.