Reciprocating pump

摘要

Pumps of this invention comprise a pump housing having at least one pressurizing chamber disposed therein, and a pressurizing member is disposed within the pressurizing chamber. The pressurizing member has a body with a solid imperforate head at one end, a thin-walled skirt extending away from the body head, and a flange extends circumferentially around a terminal edge of the skirt. A piston is disposed within the pump housing and is connected at one end to the pressurizing member. A piston gland is attached to the chamber and includes a diametrically positioned piston guide through which the piston is disposed. The flange is interposed between the chamber and the piston gland and includes sealing means to provide a fluid-tight seal therebetween. A pressurizing member plug is attached to the pressurizing member and has an outside wall surface that contacts and carries a variable portion of the skirt inside surface during reciprocating pressurizing member axial displacement. The thin-wall skirt has a 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.