The John Crane 8648SC is a standardized non-pusher elastomer, dry running, secondary containment seal designed specifically for non-crude oil hydrocarbon services, with a focus on meeting the demanding requirements of pipeline pumping station duties.
The main risk of seal failure in these applications is due to the numerous problems associated with the secondary dynamic O-ring, potentially resulting in hang-up, fretting or stub sleeve wear. The design of the 8648SC completely eliminates these common problems.
The 8648SC is used in tandem with a primary seal such as the 8648VRS. The 8648SC performs in response to the primary seal leakage or failure. In the event of the seal coming into contact with the process fluid, the faces will close and prevent a mass escape of this fluid. This represents a less complex alternative to dual unpressurized seals using a API Plan 52.