BDRP™ High Pressure Rotary Shaft Seals
BDRP Seals™ are direct compression-type rotary seals developed specifically to be hydrodynamically lubricated when high differential pressure acts from either side. This makes BDRP seals candidates for use as hydraulic swivel seals. This also makes them a candidate for use as rotating control device seals (RCD seals) with a simple gravity fed lubricant reservoir. No complicated lubricant overpressure system is required.
BDRP seals have an extrusion resistant plastic liner. This gives them the same extreme high pressure capacity as Extra Wide Plastic Lined Seals™ when pressure is applied from the wave side. With pressure applied from the opposite side, BDRP seals have been tested with 1,500 psi at 275 sfpm (139 m/s), and with 1,000 psi (6.89 MPa) at 466 sfpm (2.37 m/s).
During rotation, the waves of the BDRP Seal™ hydrodynamically wedge a lubricant film between the shaft and the plastic inner layer of the seal. This hydrodynamic interfacial lubrication reduces friction, wear, and friction-generated temperature, and enables the excellent high pressure performance of the BDRP seal.
When using a BDRP seal as a hydraulic swivel seal, two seals are required to define a single hydraulic circuit, three seals are required to define two hydraulic circuits, four seals are used to define three hydraulic circuits, and so on.
When using a BDRP seal as a rotating control device seal (RCD seal), an outboard barrier seal is required, with the region between the two seals being filled with a barrier lubricant that is balanced to the pressure of the well. The barrier seal excludes the abrasive drilling fluid but is exposed to zero differential pressure while the BDRP seal retains the pressure of the barrier lubricant.
Chapter E7 of the Kalsi Seal Handbook™ provides implementation guidelines for using BDRP type rotary seals in rotating control devices (RCDs). The most current testing and performance results can be obtained by contacting our helpful Kalsi Seals engineering team.