Abstract: A rotary shear valve assembly for liquid chromatography applications comprises a rotor assembly having a rotor and a drive shaft with a head portion. The rotor has a substantially planar surface with one or more rotor grooves and a pair of holes. The head portion has two pins. The pins are disposed substantially diametrically opposite of each other on a line through a center of the head portion. Each pin mates with one of the holes in the rotor. The rotor assembly can further comprise means for urging the rotor surface against the stator surface such that each rotor groove aligns with and provides a fluidic channel between two of the stator openings.

Abstract: Exemplary embodiments are directed to rotary shear valves which include a stator, a rotor defining a cavity extending at least partially therethrough, and a bladder. The rotor is rotatably mounted relative to the stator to create at least one fluidic path therebetween. The bladder comprises a polymer disposed inside the cavity. Exemplary embodiments are also directed to methods of operating a rotary shear valve.

Abstract: 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.

Abstract: Described is a fitting for coupling fluidic paths which facilitates secure and low leak rate fluid flow through a fluidic path junction such as a junction in a liquid chromatography system or other chemical analysis instrument. Fluid containing various mixtures of chemical samples can pass through the junction at high pressure with little or no trapped residue remaining in a volume at the connection. According to various embodiments, a face seal is achieved between two separate fluidic path features. In some embodiments, the sealing of the fluidic paths is aided by the use of a compliant polymer seal. The seal facilitates intimate contact between adjacent surfaces and significantly limits or prevents the entry of fluid under high pressure into an unswept volume. Thus the risk of carryover and its adverse effect on measurements is reduced or eliminated.

Abstract: Described is a compound sample needle for a liquid chromatography system. In one embodiment, the compound sample needle includes a rigid needle having a coupling end with a face and a counterbore. The compound sample needle also includes a flexible tubing having an outer surface and a coupling end disposed in the counterbore of the rigid needle. The coupling end of the flexible tubing has a face adjacent to a base of the counterbore. The coupling ends of the rigid needle and flexible tubing are secured to each other by a weld formed along a circumference of the outer surface and the face of the rigid needle. A rigid sleeve protects the welded joint. The compound sample needle is suitable for injection into the high pressure mobile phase of ultra performance liquid chromatography systems.

Abstract: A valve includes a rotor and a stator. The rotor and the stator each have seal surfaces for contacting and sliding against one another during operation of the valve. Either or both of the rotor and the stator have a seal-surface coating formed by depositing an at least partially amorphous interlayer on a substrate and depositing a surface layer, including diamond-like carbon, the interlayer. The surface layer requires no mechanical polishing.