Patent ID: 6402944
Filing Date: 2002-06-11
Classification: C02F,F16J,F16K,Y10T

Abstract:
A water treatment system control valve comprising:(A) a valve body which has (1) an internal bore, (2) external ports configured for connection to a source of untreated water, a treated water outlet, a brine tank, a drain, and a resin tank, respectively, (3) a plurality of internal ports opening into said internal bore, and (4) a plurality of passages connecting various ones of said internal ports to various ones of said external ports; (B) a piston which is axially slidable in said bore to connect various ones of said internal ports to one another in combinations that vary depending upon the position of said piston in said bore; and (C) a seal stack which is disposed in said bore and which sealingly surrounds said piston, said seal stack including (1) a plurality of spacers, each of which has inner and outer axial ends and inner and outer radial peripheries, (2) a plurality of elastomeric static seals, each of which is disposed between two adjacent spacers and which seals against a peripheral surface of said bore, and (3) a plurality of dynamic seals, each of which is disposed between two adjacent spacers and which seals against said piston, wherein at least some of said spacers are connected to adjacent spacers by lost motion connections that permit limited axial movement therebetween.