Abstract: The check valve (1) is of straight pipe joint type and oblique lift type. It includes: a valve seat (12a); a moving body (2) capable of linearly reciprocating between a closed state where it is in close contact with the valve seat and an open state where it is separated from the valve seat; a primary flow path (inflow path (12c)) on an upstream side of the moving body; and a secondary flow path (outflow path (12d)) on a downstream side of the moving body. The moving body includes a valve body (6) and a valve shaft (7) extending from the valve body. The valve seat supporting the valve body is formed to straddle the center line (CL) of the connection flow path that linearly extends including the primary flow path (inflow path) and the secondary flow path (outflow path 12d) in a cross section including the center line thereon.

Abstract: A safety valve includes a body having a flow passage formed therein, the flow passage including an inlet an outlet, in which a valve seat is formed around the inlet or the outlet, a disc provided in the body, in which one side of the disc is in contact with the valve seat, an elastic member that is connected to an opposite side of the disc and that elastically supports the disc and has a set elasticity, and a sealing member made of polyimide that is provided on contact surfaces of the disc and the valve seat.

Abstract: A check valve for opening/closing intake-side communication passages through which fuel passes, includes a pump body including a partition wall with the communication passages formed therein, a valve body supported by the partition wall, made of a flexible material, and formed into a plate shape, and a valve seat provided around opening portions of the communication passages on the partition wall and including a seat surface to abut against the valve body when the valve is closed, the seat surface including a groove having an opening-portion-side wall surface lying on an upstream side and an outer-side wall surface lying on a downstream side, the upstream and downstream sides being sides in a direction in which fluid passes between the valve body and the seat surface when the valve is opened, the outer-side wall surface having a gentler slope than a slope of the opening-portion-side wall surface.

Abstract: The present disclosure provides a backflow prevention device includes an upper chassis, a lower chassis, a seal member, and a resilient member. The upper chassis defines a receiving space passing through a bottom of the upper chassis. The lower chassis defines an air flow channel. A part of the lower chassis is accommodated in the receiving space of the upper chassis, and fixedly connected to an inner wall of the upper chassis. The upper chassis and the lower chassis are mounted to a pot. The seal member is received in the receiving space. The resilient member is resiliently mounted between the seal member and the upper chassis. The resilient power of the resilient member pushes the seal member to resist against and seal the air flow channel.

Abstract: Provided is a ball check valve apparatus including: a first body into which wastewater is introduced; a second body coupled to the first body to be communicated with the first body and configured to discharge the wastewater introduced into the first body; and a valve member disposed in the first body such that the valve member is movable up and down in the first body and configured to close an opening/closing hole formed in the first body by a self-weight thereof and open the opening/closing hole by a pressure of wastewater introduced through the opening/closing hole.

Abstract: An air admittance valve configured when subjected to a negative pressure condition to vent a pipe system to an ambient environment. In general, the air admittance valve includes a main body, inner and outer valve seats, a flexible sealing element, and a lid. The inner and outer valve seats define at least one vent opening between valve seats that is configured, when open, to communicate with the ambient environment. The flexible sealing element is devoid of a rigidifying structure, is configured to move to and from a closed position and an open position, and defines an outer perimeter surface, an inner perimeter surface, and opposite top and bottom surfaces extending between the outer and inner perimeter surfaces. At least one of the lid or the main body further comprises one or more guiding elements that define one or more guiding surfaces configured to guide the sealing element to and from the closed position and the open position.