Cylinder Rod Seal, 1-1/8"X1-1/2"X5/16"

Cylinder Rod Seal, 1-1/8"X1-1/2"X5/16"

The U18-1.12-31B Cylinder Rod Seal is a Style 800 polyurethane U-seal engineered for high-performance hydraulic rod sealing applications. Molded from tough 95A polyurethane, this seal features a four-lobed expander ring that energizes the sealing lips—even at zero pressure—to help prevent weeping when the system is idle. Designed for durability, abrasion resistance, and high-pressure capability, it delivers reliable sealing performance up to 5,000 PSI—because hydraulic systems should hold pressure, not lose it.

Country of Origin
Varies by production batch

Key Features / Specifications

• Product: U18-1.12-31B
• Seal Type: Style 800 Polyurethane U-Seal (Rod Seal)
• Material: 95A Polyurethane
• Inside Diameter (ID): 1.125" (1-1/8")
• Outside Diameter (OD): 1.500" (1-1/2")
• Height: 0.313" (5/16")
• Cross Section: 3/16"
• Pressure Range: 0 to 5,000 PSI
• Temperature Range: -65°F to +220°F
• Maximum Speed: 3 ft/sec
• Rod Diameter: 1.125"
• Bore / Housing Diameter: 1.500"
• Groove Width: 0.344"
• Throat Diameter: 1.126"
• Piston Diameter: 1.499"
• Weight: 0.011376 lbs

Alternate / MFG Numbers

• 187-01.125-312BUR95
• 18701125Q312B
• P18-1.12-31B
• SU-00296
• 1870-1125-312B
• 231931

Design Features

• Four-lobed expander ring energizes sealing lips
• Prevents “weeping” at zero pressure
• Excellent abrasion resistance
• Long service life in demanding hydraulic systems

Ideal For

• Hydraulic cylinder rod sealing applications
• Systems operating up to 5,000 PSI
• Equipment exposed to wide temperature swings
• Industrial, agricultural, and mobile hydraulic machinery
• Applications requiring dependable sealing at both low and high pressure