Waters Technologies Corporation

Wen Lu

Joshua A Shreve

James Usowicz

Michael R Jackson

Kurt D Joudrey

Neal B Almeida

Christopher Seith

Kara O'Donnell

Maruth Sok

Nathan Barrett

Mark W Moeller

Robert A Jencks

Carl Gang Chen

James E Usowicz

The present disclosure relates to methodologies, systems and apparatus for cooling pump heads and providing balanced cooling and heat transfer between multiple pump heads. Multi-pump systems that are used to pump fluids that vary greatly in density with minor changes in temperature, such as the mobile phase of a C02-based chromatography system, require highly stable temperature conditions. In order to achieve a substantially equal average heat transfer between multiple pump heads and a coolant fluid, coolant fluid may be flowed through coolant passageways within the pump heads in a recursive and/or parallel coolant flow patterns. Such recursive and/or parallel coolant fluid flow patterns provide increased stability in temperature, compressibility, and density of the fluids passing through a multi-pump system.

Cooling of pump heads in carbon dioxide chromatography systems

The present disclosure relates to methodologies, systems and apparatus for cooling pump heads and providing balanced cooling and heat transfer between multiple pump heads. Multi-pump systems that are used to pump fluids that vary greatly in density with minor changes in temperature, such as the mobile phase of a CO2-based chromatography system, require highly stable temperature conditions. In order to achieve a substantially equal average heat transfer between multiple pump heads and a coolant fluid, coolant fluid may be flowed through coolant passageways within the pump heads in a recursive and/or parallel coolant flow patterns. Such recursive and/or parallel coolant fluid flow patterns provide increased stability in temperature, compressibility, and density of the fluids passing through a multi-pump system.

A shear valve for use in a high performance liquid chromatography system. The shear valve includes a first valve member having a plurality of first fluid-conveying features, and a second valve member having one or more second fluid-conveying features. The second valve member is movable, relative to the first valve member, between a plurality of discrete positions such that, in each of the discrete positions, at least one of the one or more second fluid-conveying features overlaps with multiple ones of the first fluid conveying features to provide for fluid communication therebetween. At least one of the first and second valve members is at least partially coated with a protective coating that includes an adhesion interlayer and a diamond-like carbon (DLC) layer. The DLC layer is deposited on the adhesion interlayer via filtered cathodic vacuum arc (FCVA) deposition.

Valves having protective coatings

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Westborough, MA, United States of America

Wen Lu