Piston Seals

Our Style PSU piston seal, or uniring, is a laminated one piece double acting seal made of cast polyurethane. The tough outer layer is highly resistant to abrasion and is impregnated with molybdenum disulfide to reduce friction. The softer inner layer acts as a static seal and also energizes the OD to make full contact with the bore. This seal may be used to replace an existing Uniring or other seals of the same dimensions – O-rings, O-rings with back-ups, T-seals, U-seals, etc. Piston diameter “I” dimensions are given for pistons without wear rings.

60D & 57A Durometer | Urethane Composite Material | 2 in Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

Molded from tough, wear resistant 55D polyester, these seals are for light to medium duty applications and are interchangeable with the style MPS seals of the same dimensions. Nitrile rings are used for energizers.

55D; 70A Durometer | Polyester Material | 54 MM Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

Specifically designed as piston seals, these u-seals are engineered to seal on their outside diameter. They offer extended, service life and maximum reliability in piston sealing.

92A Durometer | Urethane Material | 4 1/4 in Nominal Inner Diameter | 3/8 in Cross Section | U-Seal

This capped piston seal consists of a filled PTFE cap, a T-shaped NBR energizer, and two split nylon backup rings. It exhibits low friction, high sealability, and excellent resistance to extrusion and wear.

PTFE Material | 75 MM Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

Molded from filled PTFE and machined to close tolerances, these seals feature low friction and excellent wear characteristics. Nitrile rings are used for energizers.

70A Durometer | PTFE Material | 109 MM Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

Designed to fit on one or two piece pistons, this piston seal employs a nitrile seal for high sealability, nylon split back-ups for extrusion resistance, and two split bearing rings. No further support bearings are required.

70A Durometer | NBR Material | 62 MM Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

The MPSU300 is a compact, double-acting piston seal consisting of two parts: a urethane sealing ring with a pronounced sealing edge and a rectangular nitrile energizer to prevent the seal from twisting within the groove. It also has low friction and smooth operating movement even at low linear velocities.

94A; 70/80A Durometer | Urethane Material | 37 MM Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

A heavy duty double-acting assembly, the capped piston T-seal exhibits excellent sealability, extrusion resistance, and wearability. T-seals with “BR” suffix utilize a Bronze Filled PTFE cap instead of the standard Glass Filled PTFE cap.

PTFE; Nylon; Rubber Material | 2.442 in Nominal Inner Diameter | Capped Piston T-Seal

Features

• Glass-filled PTFE cap, nylon back-up, rubber energizer

A heavy duty double-acting assembly, the capped piston T-seal exhibits excellent sealability, extrusion resistance, and wearability. T-seals with “BR” suffix utilize a Bronze Filled PTFE cap instead of the standard Glass Filled PTFE cap.

PTFE; Nylon; Rubber Material | 4.52 in Nominal Inner Diameter | Capped Piston T-Seal

Features

• Glass-filled PTFE cap, nylon back-up, rubber energizer

Caterpillar® part numbers are used as a reference only. We do not imply that these parts are original equipment parts.

4 1/2 in Nominal Inner Diameter | Piston Seal