US 11,940,424 B2
Gradient proportioning valve
Timothy M. Raymond, Milford, MA (US); Christopher Walden, Milford, MA (US); and Sean Anderson, Dedham, MA (US)
Assigned to Waters Technologies Corporation, Milford, MA (US)
Filed by Waters Technologies Corporation, Milford, MA (US)
Filed on Nov. 25, 2020, as Appl. No. 17/104,772.
Claims priority of provisional application 62/941,236, filed on Nov. 27, 2019.
Prior Publication US 2021/0156827 A1, May 27, 2021
Int. Cl. G01N 30/32 (2006.01); B01D 15/16 (2006.01); G01N 30/20 (2006.01); G01N 30/34 (2006.01); G01N 30/02 (2006.01)
CPC G01N 30/32 (2013.01) [B01D 15/163 (2013.01); B01D 15/166 (2013.01); G01N 30/20 (2013.01); G01N 30/34 (2013.01); G01N 2030/027 (2013.01); G01N 2030/205 (2013.01); G01N 2030/322 (2013.01); G01N 2030/328 (2013.01); G01N 2030/347 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A gradient proportioning valve for metering fluids in a liquid chromatography system comprising:
a plurality of inlet ports configured to receive a respective plurality of fluids from solvent reservoirs in the liquid chromatography system;
a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition that is compositionally accurate, the manifold including a plurality of conduits internal to the manifold, the plurality of inlet ports each configured to provide fluid to a respective one of the plurality of conduits of the manifold;
an actuation mechanism having a piston located within a bored structure surrounding the piston, the actuation mechanism configured to open and close at least one of the plurality of conduits in a controlled manner wherein the piston and the bored structure have a tight tolerance configured to create a fluid tight seal when the actuation mechanism closes the at least one of the plurality of conduits, wherein the tight tolerance creates a clearance of less than 6 microns between the piston and the bored structure, and wherein the piston is configured to rotate about the bored structure to open and close the at least one of the plurality of conduits in the controlled manner, wherein the actuation mechanism includes a plurality of inlet conduits each in operable communication with one of the plurality of conduits of the manifold, the actuation mechanism further including a common outlet conduit, wherein the piston includes a flat surface keyed into one side such that one of the plurality of inlet conduits is fluidly coupled to the common outlet conduit by the piston while another of the plurality of inlet conduits is blocked by the piston;
a common outlet port in fluidic communication with the common outlet conduit of the actuation mechanism, the common outlet port configured to receive the fluid composition; and
at least one accumulator chamber located downstream from at least one of the plurality of inlet ports and upstream from the actuation mechanism and the common outlet port, the at least one accumulator chamber having a compliant diaphragm disposed in a back of the at least one accumulator chamber.