Patent ID: 7509724

Claim:
A method for installing a gasket within a square gasket receiving groove provided within the bell end of a pipe section, the bell end having a mouth opening which is engageable with a spigot end of a mating pipe section to form a pipe joint, the method comprising the steps of: providing a pipe section having a bell end opening; orienting the pipe section having the bell end along a longitudinal work axis; providing a sealing gasket formed at least in part of a flexible material, the gasket having a relatively rigid internal retainer ring which circumscribes the gasket interior at one circumferential location; temporarily transforming the sealing gasket from a generally cylindrical shape to a generally elliptical shape; inserting the gasket within the mouth opening of the bell end, the annular gasket being oriented at an oblique angle with respect to the longitudinal work axis such that a trailing edge of the gasket engages the annular groove, and a leading edge of the annular gasket is moved past the annular groove provided in the bell end; exerting a retracting force on the annular gasket by pulling the leading edge thereof backwards in the direction of the mouth opening of the bell end until the gasket again assumes a generally cylindrical shape and snaps into a locked-in position within the annular groove; and wherein the location at which the relatively rigid ring circumscribes the gasket interior is selected according to the following formula: R ib = 2 â¢ D R L D + D G - 4 â¢ E G where when R ib is less than 1 gasket installation is possible, and when R ib is greater than 1 gasket installation is not possible; and where D R =retainer ring diameter; L D =distance from the bottom of the annular groove to the edge of the groove on the opposite side where the groove is formed by fillets and the distance is drawn along a line that passes through the approximate centers of the corresponding fillets; D G =diameter of the annular groove; E G =distance to the groove wall; and wherein the optimum ring location is determined by the intersection of the lines which represent D R and E G .