A choke gate valve includes a housing that defines a fluid bore and a gate that includes a throttling orifice. The gate is configured to move within the housing between a throttle position in which the gate extends across the fluid bore to position the throttling orifice in the fluid bore to throttle a fluid flow through the fluid bore and an open position in which the gate does not block the fluid bore to enable a full level of the fluid flow through the fluid bore. The choke gate valve may be used as part of a choke gate valve system to transition between first fracturing operations for a first well and second fracturing operations for a second well without shut off of a pump.

A deaeration valve includes a housing and a ball in fluid communication with housing. The ball can include a body, a seat defining a bleed passage therein, and a deaeration pin slidably disposed within the bleed passage. Further, the deaeration pin may include a head, a retention feature, and a shaft positioned between the head and the retention feature.

Example aspects of a sliding disc assembly for a dual spring valve, and a method of operating a dual spring valve are disclosed. The sliding disc assembly can comprise a shaft defining a first end and a second end; a disc mounted on the shaft between the first end and the second end, the disc defining an upper disc surface, a lower disc surface, and an annular base surface; a first spring mounted on the shaft between the lower disc surface and the first end of the shaft; and a second spring mounted on the shaft between the upper disc surface and the second end of the shaft, wherein the first spring defines a spring force that is different from a spring force of the second spring.

A poppet of a check valve includes a base, a shaft extending from the base, and a sealing head coupled to the shaft and extended away from the base by the shaft. A flow channel is defined between the base, the shaft, and the sealing head. The base includes a plurality of holes.

Example aspects of a sliding disc assembly for a dual spring valve, a dual spring valve, and a method of operating a dual spring valve are disclosed. The sliding disc assembly can comprise a shaft defining a first end and a second end; a disc mounted on the shaft between the first end and the second end, the disc defining an upper disc surface, a lower disc surface, and an annular base surface; a first spring mounted on the shaft between the lower disc surface and the first end of the shaft; and a second spring mounted on the shaft between the upper disc surface and the second end of the shaft, wherein the first spring defines a spring force that is different from a spring force of the second spring.

A gas check valve device having a header, at least one check valve plunger, at least one orifice that provides a first path for a small amount of gas to pass through the at least one check valve plunger when a respective compression spring presses the check valve plunger against a check valve seat to form an air tight seal, and a common gas passage connecting the check valve plunger with a common outlet. The gas check valve device provides a second path for a small amount of gas to pass through the orifice of the at least one check valve plunger in a reverse direction and a larger amount of the gas to pass between the at least one check valve plunger and the check valve seat when the gas pressure compresses the respective compression spring to separate the check valve plunger from the check valve seat.

A tube fitting and a tube fitting enabling a configuration that limits a through-flow rate of fluid that has passed through a flow aperture opened by a valve unit are obtained. An upstream-side choke hole in an upstream-side choke section limits the through-flow rate of the fluid. In a case in which the fluid flows at a flow rate exceeding the through-flow rate limited by the upstream-side choke hole, the valve unit opens the closed flows aperture in a flow path. A downstream-side choke hole in a downstream-side choke section disposed at a downstream side of the valve unit limits the through-flow rate of fluid that has passed through the flow aperture.

A refrigeration cycle apparatus includes a first flow switch valve including first to fourth ports, a second flow switch valve and a third flow switch valve each including fifth to seventh ports, a compressor, a discharge pipe connecting a discharge port of the compressor and the first port, a first high pressure pipe connecting between the discharge pipe and the fifth ports, a bypass expansion valve provided at a part of the first high pressure pipe, the part extending, a first outdoor heat exchanger connected to the seventh port of the second flow switch valve, a second outdoor heat exchanger connected to the seventh port of the third flow switch valve, and a controller. The controller is configured to perform a differential pressure ensuring process, when switching the second flow switch valve or the third flow switch valve. In the differential pressure ensuring process, the controller is configured to set operation frequency of the compressor to a first frequency and set opening degree of the bypass expansion valve to a first degree if a first condition is not met, and set the operation frequency of the compressor to a second frequency which is higher than the first frequency or set the opening degree of the bypass expansion valve to a second degree which is larger than the first degree if the first condition is met.

Provided is a linear solenoid valve having at least one notch that opens on an end surface of the land of the spool on the drain chamber side and is formed on an outer peripheral surface of the land. In response to movement of the spool, a state is formed in which the end surface of the land on the drain chamber side is located inside the communication chamber and the output chamber and the drain chamber communicate with each other via the notch and the communication chamber, and a state is formed in which the end surface of the land on the drain chamber side is located inside the output chamber and the output chamber and the drain chamber communicate with each other via the communication chamber.

A deaeration valve includes a housing and a ball in fluid communication with housing. The ball can include a body, a seat defining a bleed passage therein, and a deaeration pin slidably disposed within the bleed passage. Further, the deaeration pin may include a head, a retention feature, and a shaft positioned between the head and the retention feature.