Provided is a waste gate valve capable of absorbing pulsation following the pulsation of a fluid pressure. In a waste gate valve, a drive gear is rotationally driven by a drive motor, the rotational drive of the drive gear allows a valve shaft engageable with the drive gear to advance or retreat in an axial direction, and the advance or retreat of the valve shaft moves a valve provided at the valve shaft from a valve seat so as to open or close a channel. The waste gate valve includes a main spring for urging the valve in a closure direction. Fluid pressure acting on the valve is transmitted to the drive motor as a load. Furthermore, the waste gate valve includes a damper spring for urging the valve in an open direction.

A gas shut-off valve assembly designed to automatically close gas flow in a gas conduit in response to a seismic vibration comprises a door which may be parallel to a port in the conduit and a weight above the door. In some embodiments, the door may be mostly out of the conduit passageway and out of the gas flow allowing for improved gas flow efficiency in the normally open state. Upon sensing a seismic vibration, the weight falls from a platform onto the door causing the door to move into the conduit passageway sealing the passageway. In some embodiments, a port in the passageway is perpendicular to the door's default position in the open state. When the door closes the passageway, the door rotates ninety degrees about an axis into the second closed position to become parallel with the port.

A damper device may include a baffle to open/close an opening part; a motor; and a gear train connecting the motor and the baffle and including a partially toothless gear and a sector gear. The partially toothless gear may include an outer peripheral part so as to have an outer peripheral face curved along a tooth tip circle of the teeth part. The outer peripheral part may include an end face at a midway position of the teeth part in the axial line direction where a length in the axial line direction is shorter than a tooth width of the teeth part. The sector gear may include a first tooth cut out facing the outer peripheral face and configured to enter in to an inner peripheral side of the tooth tip circle. A second tooth disposed adjacent to the first tooth and configured to abut the outer peripheral face.

An operating structure of an exhaust heat recovery device may include a bypass valve rotatable about a rotation shaft to open and close a bypass passage; a heat exchanger communicating with the bypass passage, a valve actuator inserted into the heat exchanger, and having a piston moved upward and downward depending on a temperature of coolant; a guide unit in which an end of the piston is slidably inserted, and at which an end of a rod is slidably inserted; a displacement transmission medium accommodated in the guide unit, and moved along with the piston; a link unit rotatably connected to the bypass valve and the rod, and converting sliding motion of the rod into rotation of the bypass valve; and an elastic restoring unit operating the rod so that the rod is inserted into the guide unit, or operating the bypass valve so that the bypass valve is closed.

A liquid level control system, which may be used with a clarifier in a sewage treatment plant, manages liquid level of an upstream basin by controlling liquid flow in or out of a system that may use a midstream device to equally distribute flow in or out of the basin. This headloss inducing device creates a non-linear relationship between upstream liquid level to be controlled and the lesser downstream liquid level behind the gate or valve. Without the use of electrical controls, the systems of the invention include a gate or valve with counterforces that manage the outflow stream of liquid while accounting for the non-linear head loss created by the midstream device, thus reaching a desired liquid level range for all system flowrates.

Disclosed herein is an air shut-off valve for a fuel cell system that can completely close an air passage (11) communicating with a cathode of a fuel cell stack, even though a butterfly-type valve is employed, upon the halt of operation of the fuel cell system, thereby greatly improving the durability of the fuel cell stack.

A valve actuator (100) and method for controlling such is disclosed. The valve actuator (100) may include a body (126), a piston (134), a first spring (136) displaceable between a primary position (154) and a secondary position (156), and a second spring (138) displaceable between a first position (158a) and a second position (160a). The first and second springs (136, 138) are configured to be simultaneously displaced during movement of the piston (134) from a first piston position (142) to a second piston position (144). The first spring (136) is configured to compress to a higher first spring force (F.sub.1) during displacement from the primary position (154) to the secondary position (156), and the second spring (138) is configured to have a decreasing second spring force (F.sub.2) during displacement from the first position (158a, 158b) to the second position (160a, 160b), the second spring force (F.sub.2) decreasing non-linearly.

A pressure relief valve system has a fluid outlet (1) from a pressure vessel; a flexible expansion piece (4) at an end of the fluid outlet remote from the pressure vessel; a primary pressure relief valve has a valve seat and a valve lid (7). The valve seat has a flange (5) mounted on the expansion piece and the valve lid forms a valve seal with the flange. A fluid off-take (13) is connected to the fluid outlet (1) and a secondary pressure relief valve (11) receives fluid from the fluid off-take. The secondary pressure relief valve has an outlet (12) coupled to a valve opening actuator (15), whereby passage of fluid through the secondary pressure relief valve (11) causes the opening actuator to operate to open the valve lid (7).

A flap configuration opens and closes a wastegate channel in a turbine housing of a turbocharger. The flap configuration has a lever element having a through-bore in which a cylindrical bushing is arranged. A flap having a pin is arranged on the lever element such that the pin passes through the bushing. A cover disk is arranged on an opposite side from the flap and has an opening through which the pin of the flap passes. The flap is riveted to the lever element by the pin.

A cross-wall indicator post is provided to control through a wall, open and closed configurations of a piping system control valve having a manual actuator with a valve-hand wheel. The indicator post includes a post body having a mounting flange to mount the post body to a wall separating the post body from the control valve. An operating stem extends through the post body and is adjustably, slidably, non-rotatably, telescopingly engaged with an extension rod. A post-hand wheel is engaged with the operating stem for rotation thereof. An engagement member is fixedly attached to the extension rod, configured to be selectively, mechanically engageable with, and releasable from, the valve-hand wheel to actuate the control valve between the open and closed configurations thereof. Rotation of the post-hand wheel rotates the operating stem, the extension rod, and the engagement member, to, in turn, rotate the valve-hand wheel.