COLOR CHANGE VALVE ASSEMBLY

摘要

A seal assembly for sealing a valve needle having a generally circular cross section transverse to its longitudinal axis. The needle is situated inside a valve assembly including a housing having a longitudinal axis. The needle controls flow of a fluid from a fluid supply line to a fluid outlet passage. The seal assembly comprises a seal positioner including a cylindrical body portion surrounding the needle and having a first end, a second end, and an inner side wall having a cross section larger than the cross section of the needle to define a space between the inner side wall and the needle. The seal positioner also includes a partition for coupling the body portion to the needle to align the body portion concentrically with the needle and to maintain the concentric alignment upon misalignment of the longitudinal axis of the needle and the longitudinal axis of the valve assembly. The partition provides first and second sealing regions spaced longitudinally along the needle. A first seal in the first sealing region extends perimetrally around the needle and contacts a first portion of it. A second seal in the second sealing region extends perimetrally around the needle and contacts a second portion of it.