Varian Associates

About: Varian Associates is a based out in . It is known for research contribution in the topics: Beam (structure) & Amplifier. The organization has 2160 authors who have published 2591 publications receiving 46002 citations.

High pressure sample injection apparatus and method

Abstract: A high pressure sample injector for liquid chromatographs is disclosed. The apparatus includes structure defining a cylindrical dispensing chamber for receiving the sample to be injected into the flow path of a high pressure stream of carrier fluid in a liquid chromatograph. Control structure is interposed between the dispensing chamber and the flow path of the carrier stream for preventing liquid flow from the carrier stream to the dispensing chamber, and for enabling flow in the opposite direction only when the pressure in the dispensing chamber at least equals the carrier stream pressure. A pressurizing apparatus is connected to the dispensing chamber to raise its pressure, when desired, to a value at least equal to that of the carrier stream, in order that the sample may be injected into the carrier without reducing the carrier stream pressure.

Rotating sealing device

Abstract: A rotating sealing device for sealing between a wall separating two mediums under substantially different pressure and a rotatable shaft utilizes a combination of a liquid metal seal comprising at least one liquid metal ring and a shield means which prevents contamination of the metal ring by gases coming into contact with the liquid metal. Magnetic fluid seal, a ring of an oil material, or inert gas may be used as a shield to protect the liquid metal.

Gas ballast for oil sealed mechanical vacuum vane pump

Abstract: A gas ballast device for an oil sealed mechanical rotary vane vacuum pump prevents vapor condensation in the outlet port region of the low vacuum stage of the pump as a vane cyclically approaches the outlet port, whereby molecules of condensed vapor in the oil do not flow back to the inlet port of the low vacuum stage through the oil seal between the inlet and outlet ports. A flow path for atmospheric air leading to the outlet port region includes a tortuous, constricted fluid passageway. An outlet passage connecting the tortuous, constricted fluid passageway to the outlet port region is positioned so that an orifice thereof into the outlet port region is filled with and sealed by oil except during a small portion of each vane cycle immediately after the vane passes the orifice, whereby no movement of mechanical parts is employed to control air flow in response to the cyclical movement of the vanes past the orifice. The flow path for atmospheric air can be adjusted or closed at will, and includes a sleeve through which a portion of the passageway extends. The sleeve is spring biased in an upward direction to be normally urged against an air filter body, threadedly secured to a housing for the pump. The spring bias and turning of the air filter body move a plug relative to a seat in the outlet passage. The air filter body may be removed without removing the sleeve from the housing.