Patent ID: 6079959
Filing Date: 2000-06-27
Classification: F04B

Abstract:
A pump for pressurizing process fluid comprising:a pump housing having at least one pressurizing chamber disposed therein, wherein the pressurizing chamber comprises a substantially closed chamber end at one axial end and an open chamber end at an opposite axial end, and wherein the substantially closed chamber end is in hydraulic connection with a fluid transport passageway;a pressurizing member disposed within the pressurizing chamber, the pressurizing member having a one-piece construction formed from a fluoropolymeric material and including:a generally cylindrical body having a solid imperforate head at one body end that is positioned adjacent the closed chamber end;a thin-wall skirt extending away from the body head and having an inner and outer surface; anda flange extending circumferentially around a terminal edge of the skirt;a piston disposed axially within the pump housing and connected at one end to the pressurizing member opposite the body head;a piston gland attached to the open pump chamber end and having an inside diameter that is complementary to that of the pressurizing chamber, wherein the piston gland includes a diametrically extending portion with a piston opening for accommodating the piston therethrough, and wherein the pressurizing member flange is interposed between the pressurizing chamber and the piston gland and includes sealing means to provide a fluid-tight seal therebetween;a pressurizing member plug attached to the pressurizing member and extending a distance axially away from the body head towards the piston, the plug having an outside wall surface that contacts and carries a variable portion of the skirt inside surface during reciprocating pressurizing member axial displacement;wherein the pressuring member thin-wall skirt has sufficient axial length to roll between the plug outside wall surface and the gland inside diameter to permit pressurizing member reciprocating axial displacement within the pressurizing chamber.