The OHM piston seal is a two-piece heavy-duty piston seal designed for double-acting hydraulic cylinders, serving as the high-pressure counterpart to the OK seal . It consists of a glass-fiber reinforced PTFE slide ring and an NBR elastomer energizer . This construction provides extremely high extrusion resistance, excellent chemical compatibility, and low friction across a wide temperature range . The open design allows for easy installation on one-piece pistons .
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Product Overview
The OHM piston seal is a high-performance sealing solution engineered for the most demanding hydraulic applications. Similar to the OK seal but designed for higher operating temperatures, the OHM features a glass-fiber reinforced PTFE slide ring paired with an NBR elastomer energizer .
The seal features a split design that allows for easy installation on one-piece (solid) pistons without the need for special tools . Once installed into the bore, the seal diameter is compressed to close the cut, providing excellent, drift-free sealing performance .
How It Works
The OHM seal operates through a combination of energizer preload and pressure activation. The rectangular NBR energizer provides initial sealing contact with the cylinder bore. As system pressure increases, the hydraulic fluid activates the energizer, which pushes the PTFE slide ring outward against the cylinder wall, creating a self-energizing sealing effect .
The glass-fiber reinforced PTFE slide ring provides excellent extrusion resistance, low friction for smooth operation, and superior chemical compatibility .
Specifications and Parameters
| Parameter |
Detail |
| Product Name |
OHM Piston Seal |
| Type |
Two-piece heavy-duty piston seal |
| Slide Ring Material |
Glass-fiber reinforced PTFE (Polytetrafluoroethylene) |
| Energizer Material |
NBR (Nitrile Butadiene Rubber), ~70-80 Shore A |
| Working Pressure |
Up to 400 bar / 40 MPa |
| Temperature Range |
-30°C to +150°C |
| Working Speed |
≤ 5 m/s |
| Application |
Piston seal for double-acting hydraulic cylinders |
Product Features
1. Excellent Chemical Compatibility
The PTFE slide ring offers outstanding resistance to almost all hydraulic fluids, including mineral oils, water-glycol, phosphate esters, and aggressive chemicals.
2. High Temperature Capability
With a maximum operating temperature of 150°C, the OHM seal is suitable for high-temperature hydraulic applications where standard PU seals would fail.
3. Low Friction & No Stick-Slip
PTFE provides an extremely low coefficient of friction, reducing wear and eliminating stick-slip (crawling) behavior even at low speeds. Maximum operating speed up to 5 m/s .
4. High Extrusion Resistance
The glass-fiber reinforced PTFE material provides excellent resistance to extrusion, ensuring reliable performance under high pressure and with large clearances . This allows for larger piston-to-cylinder gaps, reducing machining costs .
5. Split Design for Easy Installation
The open split design allows for straightforward installation on one-piece pistons without special tools .
6. Good Dynamic & Static Sealing
Provides excellent sealing performance in both dynamic and static conditions across a wide temperature range .
Need OHM heavy-duty piston seals for your high-temperature hydraulic applications?
Contact SANPING SEAL today with your bore size and application requirements. Our team will provide a free quote within 24 hours.
