Patent ID: 7234704
Filing Date: 2007-06-26
Classification: F16J

Abstract:
1. A process for sealing a movable piston, comprising the steps of: providing a piston housing with means defining a groove having an opening, an opposite groove radially outer limitation, an axially inner shoulder and an axially outer shoulder; inserting a seal into the groove, the seal being a quad ring with four sides and with four lips, with each side being between adjacent lips; after inserting said seal into said groove, rotating the cross section around a center of the quad ring such that only one of said lips is in sealing contact with said piston, at least one of said lips is in sealing contact with said axially inner shoulder and at least one of said lips is in sealing contact with said axially outer shoulder; and moving said piston axially in each of an outer axial direction and an inner axial direction with said one of said lips in sealing contact with said piston, at least one of said lips is in sealing contact with said axially inner shoulder and at least one of said lips is in sealing contact with said axially outer shoulder.