A buffer valve is installed on a pneumatic diaphragm valve. An inner flow channel of the buffer valve includes an inner micro gas hole, an inner chamber, an outer gas hole, and a floating ball. The buffer valve has functions with a high-filling action, a shielding action, a releasing action, a shielding time t, and an adjusting mechanism. When inflatable, the floating ball will not block the inner micro hole to be quickly filled with high-pressure gas. when gas discharge, the floating ball will move to the outer gas hole with the gas flow and produce the shielding action to reduce the discharge rate to reduce the vibration and slow down the approach speed of the diaphragm to reduce the impact against the valve seat. When the pressure of the gas decreases, the floating ball is separated from the outer gas hole by the releasing action to accelerate the discharge.

A pump assembly is disclosed. The pump assembly including an outer casing having a first end, an opposing second end, and a cavity therein; a discharge tube positioned in the cavity and exiting the first end of the outer casing; a check valve positioned in the cavity and operably connected to the discharge tube by a coupling; and a multi-float control assembly positioned in the cavity, the multi float control assembly including a bottom float check valve operably connected to the discharge tube by the coupling and an upper float check valve connected to a vent exiting the first end of the outer casing.

A variable flow check valve device is proposed comprising an inlet connected with a first pressure fluid reservoir, an outlet connected with a second pressure fluid reservoir, which is separate and/or separable from the first pressure fluid reservoir, a check valve closing member configured to open and to close the outlet in response to a pressure difference of the pressure fluid on opposite sides of the check valve closing member, and a spool valve with a movable spool disposed in a flow path of the pressure fluid extending from the inlet to the outlet, the spool valve forming a variable orifice within the flow path of the pressure fluid, wherein the variable flow check valve device further comprises a force balancing unit disposed in the flow path of the pressure fluid and configured to create a balancing force to at least partially counteract a force acting on the spool when the pressure fluid passes the at least partially opened spool valve.

A valve device (2), of a pneumatically actuatable friction clutch engageable by spring force, includes at least one inlet valve (16, 18) connected on the input side to a pressurized supply line and on the output side to an actuating cylinder of the friction clutch. A pressure-sustaining valve (20, 28) is upstream or downstream of the inlet valve and is designed as a check valve closing in the backflow direction. The pressure-sustaining valve is a springless check valve and includes a housing ring (22, 30) having a retaining basket (36), a closing element (24, 32), and a valve seat (26, 34). The closing element, in the depressurized state and with a positive pressure gradient is held in the retaining basket (36) of the housing ring (22, 30) and, with a negative pressure gradient is pressed out of the retaining basket (36) and against the valve seat (26, 34).

A pressure regulation valve including a pilot stage valve with a ball valve body and a conical seat. A shock absorber with at least one pressure regulation valve.

A variable flow check valve device includes an inlet connected with a first pressure fluid reservoir, an outlet connected with a second pressure fluid reservoir, which is separate and/or separable from the first pressure fluid reservoir, a check valve closing member that opens and closes the outlet in response to a pressure difference of the pressure fluid on opposite sides of the check valve closing member, and a spool valve with a movable spool in a flow path of the pressure fluid extending from the inlet to the outlet. The spool valve forms a variable orifice within the flow path of the pressure fluid. The variable flow check valve device includes a force balancing unit in the flow path which creates a balancing force to at least partially counteract a force acting on the spool when the pressure fluid passes the spool valve.

A vacuum pump includes a motor, a pump coupled to the motor to receive torque therefrom, and a trestle including an inlet port, an outlet port, and a fluid pathway therebetween, the outlet port being fluidly connected to the pump. The vacuum pump also includes a first valve positioned within the fluid pathway and adjustable between an open state, in which an airflow induced by the pump is drawn through the inlet port, and a closed state, in which a reverse airflow through the inlet port is prevented, and a second valve positioned within the fluid pathway in series with the first valve and adjustable between an open state, in which the airflow induced by the pump is drawn through the inlet port, and a closed state, in which the reverse airflow through the inlet port is prevented when the motor is deactivated.