Piston Seals

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

4 1/4 in Nominal Inner Diameter | Piston Seal

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

90A Durometer | Nitrile Material | 1 3/8 in 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 1/2 in Nominal Inner Diameter | 1/4 in Cross Section | U-Seal

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 | 7 1/4 in Nominal Inner Diameter | 3/8 in Cross Section | U-Seal

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 | 9 in Nominal Inner Diameter | 1/2 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 | 60 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 | 59 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 | 79 MM Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

Manufactured from 55 Shore D polyester reinforced with <5% glass fiber, style PS1704 offers compact, low friction sealing for light to medium duty hydraulic cylinders. Style PS1704 is easily stretched over the piston without needing to be resized as in the PS1400 seals. Directly interchangeable with style PS1400 and PS1500 piston seals. Piston diameter “I” dimensions are given for pistons without wear rings.

70A Durometer | Poly-Trel™ Thermoplastic Material | 1.606 in Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities

The Style PSC is a double acting piston seal designed to replace o-rings, quad-rings, and T-seals with the same groove dimensions (O-ring dash number). Style 575 urethane back-up rings may be added to either or both sides of the “PSC” to accommodate wider groove widths. The PSC is made of 95A Durometer polyurethane, giving it high extrusion and abrasion resistance. The crowned sealing surface produces a positive seal from vacuum to high pressure. Hercules® Sealing Products also offers a wide base (WB) Style PSC piston seal. These wide base seals have the same characteristics of the standard PSC seals but offer a wider base, eliminating the need to use back-up rings to accommodate wider grooves. Piston diameter “I” dimensions are given for piston without wear rings.

95A; 70A Durometer | Polyurethane Material | 2 7/8 in Nominal Inner Diameter | Piston Seal

Features

• Easy assembly
• Low friction capabilities