Patent ID: 8382067

Claim:
A stem cylinder seal comprising: a bushing as a sealing member and upper and lower conical sockets, the bushing being compressed between the upper and lower conical sockets and not needing any restriction from a stuffing box, the upper and lower conical sockets and the bushing being configured to receive a movable stem therethrough, the upper conical socket being integrated in a gland, and the lower conical socket being integrated at the outside of a thrust step of an exit opening through which the movable stem extends; wherein a section of the bushing is a truncated triangle with an untruncated side of the truncated triangle being the generatrix of a cylindrical inner surface of the bushing used for sealing the stem cylinder, a truncated side of the truncated triangle being the generatrix of a first tapered outer surface of the bushing used for sealing the lower conical socket, and the other truncated side of the truncated triangle being the generatrix of the other second tapered outer surface of the bushing used for receiving a compressive force from the gland, and the truncating side of the truncated triangle being the generatrix of the short cylindrical outer surface of the bushing used for providing a wearing and compressing allowance for the bushing.