A valve device for a gas tank, includes a body and a check valve provided in an injection passage to inject gas into the gas tank. The check valve includes a valve seat, a case fixed in the injection passage while a space is provided between an inner peripheral surface of the injection passage and the case to enable gas to flow through the space, and a valve element accommodated in the case. The case includes a cylindrical portion, and is configured such that the bottom of the cylindrical portion, provided at an opposite side to the valve seat, defines a range where the valve element is axially movable. The valve element includes a head portion that can block a valve hole of the valve seat, and a sliding portion formed to be axially movable with respect to the cylindrical portion.

A two-part housing interconnects inlet and outlet fittings in fixed relation to form a valve body having an elongate internal chamber. The chamber includes a piston having a seal and cyclically slidable from a closed, flow-restricting position, to an open position. A cam within the chamber engages a follower on the piston outer surface and is driven by an external handle. Certain valve bodies are formed by connecting inlet and outlet fittings. An actuator includes a two-part collapsible cam insertable through the chamber and into a bonnet. Following piston installation, the cam is extended by an external handle to engage a follower on the piston surface. Another actuator includes a body-encircling ring having a cam track on the interior surface. One end of a follower engages the track and another end engages the piston. Rotation of the ring and track drives the piston within the chamber to control liquid flow through the valve.

A shut-off valve 1 is a shut-off valve arranged on the downstream side with respect to an exhaust port of a vacuum pump, and includes a valve seat, a valve element, and a pressure receiving portion. The valve element is arranged on the downstream side with respect to the valve seat, and is configured movable so as to contact the valve seat or separate from the valve seat. The pressure receiving portion is arranged on the downstream side with respect to the valve element, and is movable to the valve seat by receiving the pressure of gas flowing back to the valve seat. The valve element is connected to the pressure receiving portion, and moves to the valve seat along with movement of the pressure receiving portion to the valve seat.

A valve device for a gas tank, includes a body and a check valve provided in an injection passage to inject gas into the gas tank. The check valve includes a valve seat, a case fixed in the injection passage while a space is provided between an inner peripheral surface of the injection passage and the case to enable gas to flow through the space, and a valve element accommodated in the case. The case includes a cylindrical portion, and is configured such that the bottom of the cylindrical portion, provided at an opposite side to the valve seat, defines a range where the valve element is axially movable. The valve element includes a head portion that can block a valve hole of the valve seat, and a sliding portion formed to be axially movable with respect to the cylindrical portion.

A first on-off valve 2 and a second on-off valve 3 each are a two-port valve. A first passage block 5 is provided with a first on-off valve-corresponding inflow passage 11 and a first on-off valve-corresponding outflow passage 12. A second passage block 6 is provided with a second on-off valve-corresponding inflow passage 14 and a second on-off valve-corresponding outflow passage 15. The second on-off valve-corresponding outflow passage 15 is in communication with an upstream side portion of the first on-off valve-corresponding outflow passage 12 via a communicating passage 13 formed in the first passage block 5. An orifice 20 is provided between the second on-off valve-corresponding outflow passage 15 and the communicating passage 13.

A diaphragm pump such as a three-chamber diaphragm pump includes a head having an inlet port and an outlet port and defining an inlet side including inlet chambers; and an outlet side having a center outlet chamber. Each of the inlet chambers includes an associated inlet valve. A single shutoff valve controlling fluid flow to the center outlet chamber and a single bypass valve in fluid communication between the center outlet chamber and the inlet side. The single shutoff valve has a plunger with an oval cross-section extending into the center outlet chamber. The single shutoff valve and the single bypass valve have adjustable pressure set points that are adjustable independently of one another.

A piping plug includes a housing including a through-hole, and a filter device that is inserted into the through-hole and provided in the housing, the filter device includes a holder including a holder passage having a first opening and a second opening, and a filter provided in the holder so as to cover the first opening, the first opening is located on an outer circumferential face of the holder, the second opening is located at one end of the holder, and the holder is cantilever-supported by the housing in one end side part of the holder such that a clearance is left around the outer circumferential face.

A diaphragm pump such as a three-chamber diaphragm pump includes a head having an inlet port and an outlet port and defining an inlet side including inlet chambers; and an outlet side having a center outlet chamber. Each of the inlet chambers includes an associated inlet valve. A single shutoff valve controlling fluid flow to the center outlet chamber and a single bypass valve in fluid communication between the center outlet chamber and the inlet side. The single shutoff valve has a plunger with an oval cross-section extending into the center outlet chamber. The single shutoff valve and the single bypass valve have adjustable pressure set points that are adjustable independently of one another.