The technology generally relates to tailoring a back pressure regulator in a chromatographic system to reduce unswept volume within the back pressure regulator to achieve better sample detection and a reduction in chromatographic band distortion effects.

The technology generally relates to tailoring a back pressure regulator in a chromatographic system to reduce unswept volume within the back pressure regulator to achieve better sample detection and a reduction in chromatographic band distortion effects.

A valve is provided, the valve including a housing; and a valve element, the housing comprising a cylindrical bore defining an axial direction and an annular shoulder extending into the cylindrical bore, wherein the valve element is axially moveable within the cylindrical bore so as to move the valve element between a closed position in which the valve element engages with the annular shoulder and an open position in which the valve element is spaced from the annular shoulder, wherein, in the open position, fluid flowing into the valve in a first axial direction may flow through one or more apertures provided in the valve element and through the valve, wherein the valve element and the annular shoulder are configured to be in continuous contact along an annular contact surface when in the closed position so as to seal against fluid flow through the valve.

A water stop switch device includes: a main body, a transmission element and a sealing element; the main body is disposed with a water passage, the sealing element is disposed in the water passage; one end of the sealing element is coupled to the transmission element in transmission way, the sealing element moves in the water passage to open the water passage; the other end of the sealing element and the main body surround to form a chamber; the side wall of the sealing element is disposed with a through hole connecting the water passage and the chamber; when the water passage is open, the chamber is full of water to reduce the pressure difference at two ends of the sealing element.

A sealing valve is provided with a valve seat including a valve hole, a valve element to open and close the valve hole, and a seal member to seal between the valve element and the valve seat during full closing. The seal member includes a fixed part fixed to the valve seat, a contact part to be brought into contact with a seal surface of the valve element, and a constricted part provided between the fixed part and the contact part. The contact part is rotatable about the constricted part.

A check valve having a valve that is movable by incoming water in the flow direction, from a closed position, where it bears against a first valve seat, against a restoring force into an open position, where it is raised from the first valve seat, and having a pressure relief valve with a closing member that is movable by pressure of the water flowing back against the flow direction, from a closed position, in which it bears against a second valve seat, against a restoring force into an open position where it is raised from the second valve seat. The restoring force acting on the closing member is greater than the restoring force acting on the valve body. The closing member has a closing member core made of a first material, and at least in the partial region thereof that abuts the second valve seat in the closed position, has a film or a layer made of a second relatively softer and/or elastic material.

Valves and valve assemblies are described herein employing architectures which can mitigate degradative wear mechanisms, thereby prolonging life of the assembly. In one aspect, a valve comprises a head including a circumferential surface and a valve seat mating surface comprising sintered cemented carbide. Leg members extend from the head, wherein thickness of one or more of the leg members tapers in a direction away from the head to induce laminar fluid flow around the head. In some embodiments, the sintered cemented carbide is an inlay coupled to the valve head.

An oil pressure supply device supplies, to an oil chamber, an oil pressure generated by suctioning oil from an oil source with an oil pump. The oil pressure supply device includes a first oil passage connected to a suction side of the oil pump; a first check valve provided in the first oil passage and configured to close the first oil passage and prevent oil from moving to the oil source side when the oil pump is stopped; a second oil passage connected to a discharge side of the oil pump; and a second check valve provided in the second oil passage and configured to close the second oil passage and prevent oil from moving to the oil pump side when the oil pump is stopped. When the oil pump is stopped, the second check valve closes the second oil passage earlier than the first check valve closes the first oil passage.

A fluid shut-off device has a valve body delimiting an inlet duct and an outlet duct and having an intermediate portion delimiting an intermediate chamber that provides fluid connection between the inlet and outlet ducts. The inlet duct has an inlet duct connection edge. The intermediate chamber has a sealing surface and accommodates a diaphragm having a diaphragm sealing portion that in a closing position of the inlet duct, cooperates, by a diaphragm support surface, with the sealing surface to occlude the inlet duct. The diaphragm has a diaphragm bending portion permanently connecting the diaphragm sealing portion to the valve body to exclusively operate under bending. The diaphragm sealing portion delimits a diaphragm seat. A control element has a control stem with predetermined transverse control stem dimension and integrally received in the diaphragm seat, which transmits movement to the diaphragm sealing portion at least between the closing position and an opening position of the inlet duct.

A valve block includes a fluid-transfer plate with multiple inlet bores connecting to a common inlet channel, and multiple outlet bores connecting to a common outlet channel. The inlet bores and the outlet bores are arranged in a curved shape. The valve block also includes a pressure plate and diaphragm aligned and connected to the fluid-transfer plate in a way that allows pressurized material in the pressure plate to control the state of the channels formed by the inlet and outlet bores.