6-3/4" x 7-1/4" x 0.105" Urethane Backup Ring

6.750" x 7.250" x 0.105" (171.45 mm x 184.15 mm x 2.67 mm)

DESCRIPTION

Our 8-U 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 much improved extrusion resistance over our 8-N Nitrile backup rings. 

Our 8-U 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 8-U 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 8-U 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 

Extrusion Gap at Various Pressures (in):

• 2,000 PSI: 0.010
• 4,000 PSI: 0.006
• 6,000 PSI: 0.004
• 8,000 PSI: 0.002
• 10,000 PSI: 0.000 (METAL-TO-METAL CONTACT REQUIRED)

Max Speed (ft/sec): 3.0 

Mating Surface Roughness - Ra (µin) - DYNAMIC: 4<>16 

Mating Surface Roughness - Ra (µin) - STATIC: 63 MAX 

Part Number Definition (Inch): 8-(AS568 3-DIGIT NUMBER)U 

Additional Part Number Definition (Inch): 2"ID X 1/8" NOMINAL CS = 8-226U