DESCRIPTION
The MKR profile is a rod seal that can be used as a buffer seal in conjunction with other primary rod seals or in tandem with itself, creating a zero leak seal. The MKR is a uni-directional seal, with a unique design that allows the seal to relieve pressure build up. This pressure relief feature allows the MKR to be used in a tandem or multiple seal arrangement.
The MKR features low friction, long life, and versatility. When the rod is going through its power stroke (higher pressure) the seal is riding on a sealing point, creating a high compression point and limiting leakage. As the rod goes to its return stroke, it rocks forward, creating a larger sealing surface on the rod. The compression force is spread out over a larger area, reducing the load on the rod. This allows any trapped fluid to easily return to the system.
When using the MKR series as the primary seal, a double-acting wiper must be used to contain fluid until rod retraction allows return of the fluid into the system. With strokes of more than 3 feet, the gland must be designed to provide an oil storage chamber between the seals. Please consult the H&D technical group for more information.
For high temperature applications, the MKR-V seal can be used. Temperature rating is -20 to 400F and uses a Fluorocarbon energizer in place of standard Nitrile
SEAL INFORMATION
Material Type (Primary Seal): 40% BRONZE-FILLED PTFE
Material Type (Energizer): 70A NITRILE
Material Type (Energizer): 75A FLUOROCARBON
Durometer (Shore D): 63
Temperature Range (F) NITRILE: -40 TO 220
Temperature Range (F) FLUOROCARBON: -20 TO 400
Max Pressure (psi): 5000
Extrusion Gap at Various Pressures (mm):
- 1,500 PSI: 0.70
- 2,900 PSI: 0.40
- 5,800 PSI: 0.25
Max Speed (ft/sec): 49.0
Mating Surface Roughness - Ra (µm) - DYNAMIC: 0.1<>0.4
Mating Surface Roughness - Ra (µm) - STATIC: 1.6 MAX
Part Number Definition (Metric): MKR-(ROD DIAMETER)X(OD)X(SEAL HEIGHT) - ADD -V FOR FLUOROCARBON ENERGIZER
Additional Part Number Definition (Metric): 70 X 85.5 X 5.9 = MKR-70X85.5X5.9 (OR MKR-70X85.5X5.9V