DESCRIPTION
Our MBU backup rings help prevent extrusion in high pressure service and compensate for loose fitting parts. These backup rings are molded from a tough abrasion-resistant 95-duromenter Polyurethane and provide excellent extrusion resistance.
Our MBU backup rings are generally usable through a temperature range of -65 to 220 and is not intended for use with water-based fluids.
In double-acting seal assemblies, an MBU backup is required on both sides of the o-ring. It is cheap insurance to use two even in single acting installations. At assembly, it is too easy to place a single MBU backup on the wrong side of the o-ring. By specifying one on each side of the o-ring, there be one on the low pressure side, where it is needed, and the extra 8-U backup does no harm.
SEAL INFORMATION
Durometer (Shore A): 95
Temperature Range (F): -65 TO 220
Max Pressure (psi): 10000
Extrusion Gap at Various Pressures (mm):
- 2,000 PSI: 0.25
- 4,000 PSI: 0.15
- 6,000 PSI: 0.10
- 8,000 PSI: 0.05
- 10,000 PSI: 0.000 (METAL-TO-METAL CONTACT REQUIRED)
Max Speed (ft/sec): 3.0
Mating Surface Roughness - Ra (µm) - DYNAMIC: 0.1<>0.4
Mating Surface Roughness - Ra (µm) - STATIC: 1.6 MAX
Part Number Definition (Metric): MBU-(ID)X(CS)X(HT)
Additional Part Number Definition (Metric): 70 X 75 X 1.3 = MBU-70X2.5X1.3