Patent ID: 6505639
Filing Date: 2003-01-14
Classification: F16K,Y10T

Abstract:
A three-way valve comprising:(a) a fluid product dispensation housing having at one end a piston activation housing and an outlet port at the other end and an elongated product chamber and a cylindrical passage connecting said outlet port with said elongated product chamber and a first inlet port and a second inlet port communicating with said elongated product chamber disposed intermediate said piston activation housing and said outlet port; (b) a piston rod disposed in a substantially confronting cylindrical piston rod wall portion in said cylindrical passage said piston rod having a sealing head disposed on said piston rod, said sealing head having a diameter greater than said piston rod and disposed in said elongated product chamber intermediate said first inlet port and said second inlet port; (c) a tapered wall in said elongated product chamber intermediate said first inlet port and said second inlet port said tapered wall forming a sealing seat for said sealing head; (d) a leak detection port disposed in said fluid product dispensation housing connecting a portion of said substantially confronting cylindrical piston wall portion of said cylindrical passage with an ambient environment said leak detection port providing an unsealed piston rod and substantially confronting cylindrical piston rod wall to always openly connect a portion of said cylindrical piston rod wall to said ambient environment; (e) a first fixed seal disposed intermediate said leak detection port and said elongated product chamber, said first fixed seal having a hole therethrough for surrounding said piston rod and sealing said elongated product chamber from said leak detection port; (f) a second fixed seal disposed intermediate said leak detection port and said piston activation chamber, said second fixed seal having a hole therethrough for surrounding said piston rod and sealing said piston activation housing from said leak detection port; (g) a piston activation housing having pneumatic means for maintaining positive control of said sealing head with respect to said first inlet port and said second inlet port and said sealing seat for accurately dispensing fluid products having a variety of physical properties related to density, temperature and pumping pressure through said outlet while providing a positive indication as to seal failure as between said first seal and said second seal to prevent cross contamination between products dispensed through said outlet and fluid within and said pneumatic means.