The present invention discloses a gate valve with a first side and a second side relative the throughbore. A circular body cavity is on the first side and a rectangular body cavity on the second side and a portion of the first side whereby the gate is operable to move up and down within the body cavities. Due to the rectangular body cavity, the seats are slimmer than the gate. A skirt assembly is used which is inserted over the gate to cover the gate opening when the gate is moved to the closed position to prevent debris and other contaminants from entering the body cavity. Four U-shaped seals are mounted to provide that the gate valve is a bidirectional gate valve with upstream sealing having back up downstream sealing in case an upstream seal fails.

A valve stem retainer device may include a housing that holds a valve stem. The housing may prevent the valve stem from closing without control. The device may include at least one bracket that holds on to the housing. The device may include a steel rod that holds on to the housing. The steel rod may support the at least one bracket. The device may include a double set of a washer and a nut that ensures a tight and secure connection between the at least one bracket and the housing.

A system includes a split gate valve with first and second gate sections coupled together and configured to move together within a cavity of the split gate valve between an open position and a closed position. The split gate valve includes a rolling actuator to reduce friction and to convert a rotational input into a linear motion to move the first and second gate sections between the open and closed positions. The split gate valve also includes at least one expansion bar configured to bias the first and second gate sections from one another to seal against opposite seats of the split gate valve, wherein each expansion bar includes a spring mechanism configured to compress upon moving the first and second gate sections into and beyond the closed position to prevent buckling of the expansion bar.

An adjustable orifice valve system is disclosed which comprises an iris valve to control flow rate through the system, and a slide valve to prevent leaks through the system. Both valves can be adjusted through a gear train manually via a handle and/or automatically via a motor. When the iris valve is in a minimally open configuration, the gear train engages the slide valve to permit or disallow flow through the slide valve. When the iris valve is in a partially or maximally open configuration, an opening in the slide valve is aligned with the flow axis of the system to permit uninhibited flow through the slide valve. The position of the handle can indicate aperture size of the iris valve and/or position of the slide valve. In some embodiments, a pressure transducer and/or gear position sensor can provide determination of flow rate through the valve system.

A valve actuator assembly having an actuator housing coupled to a bonnet and a housing lid. A hydraulic cylinder is positioned within the actuator housing and directly coupled to the bonnet. A piston is positioned within the hydraulic cylinder and coupled to a spring lifter assembly and a spring is positioned within the actuator housing and having a first end and a second end, the first end being coupled to a lower surface of the housing lid, and the second end being coupled to the spring lifter assembly. An operating stem is coupled to the piston and positioned in a channel extending through the bonnet to a valve body assembly.

A blast gate for a vacuum system includes a chassis connectable to a duct and defining a flow passage therethrough, and a gate connected to the chassis and rotatable about a central axis. The gate includes a first portion, an intermediate portion and a second portion spaced apart circumferentially about the central axis. The first portion defines a flow aperture, the intermediate portion defines an auxiliary flow aperture, and the second portion includes a partition. Each of the first portion, second portion and third portion is selectively rotatable into fluid alignment with the flow passage. The blast gate further includes a motor connected to the gate and selectively operable to rotate the gate about the central axis.

A hydraulic valve arrangement (1) is provided comprising comprising a supply port arrangement having a high pressure port (2) and a low pressure port (4), a working port arrangement having two working ports (6, 7), a first valve (13) arranged between said high pressure port (2) and said working port arrangement (6, 7), a second valve (14) arranged between said low pressure port (4) and said working port arrangement (6, 7), a controller (19) for controlling said first valve (13) and said second valve (14), said controller (19) having an input connection (20) for receiving a signal of an operator input device, and a regenerative flow path which can be established by means of at least one of said first valve (13) and said second valve (14). The function of such a hydraulic valve arrangement should be enhanced. To this end said controller (19) said controller interrupts said regenerative flow path when a feed pressure at said working port arrangement (6, 7) exceeds a predetermined pressure level.

The invention concerns an operator assembly having a tubular housing extending along a central axis (X1) and a transmission mechanism arranged in an inner bore of the housing and extending along the central axis (X1). The transmission mechanism providing a screw with a threaded outer surface and a nut with a threaded inner surface. The nut is radially mounted around the screw and the inner thread is configured to cooperate with outer thread. The operator assembly further provides angular contact bearings that are radially arranged between the inner bore of the housing and an outer surface of the rotating nut to support in rotation and guide the nut within the housing. The angular contact bearings are axially adjacent and are disposed within an angular contact ball bearing and an angular contact roller bearing.

A gas valve unit for controlling a gas throughput routed to a gas burner of a gas appliance includes a valve housing, an actuation shaft which is able to set an opening cross section of the gas valve unit, and a stop valve. A linearly-displaceable connection element transmits a movement of the actuation shaft to the stop valve. The connection element has a plastic bend forming an overpressure protection.

A method of controlling chemical concentration in electrolyte includes measuring a chemical concentration in an electrolyte, wherein the electrolyte is contained in a tank; and increasing a vapor flux through an exhaust pipe connected to the tank when the measured chemical concentration is lower than a control lower limit value.