General
The piston seal kit OHP is a double-acting sealing element consisting of a PTFE ring for dynamic sealing (primary seal) and an O-ring as an elastic preload element (secondary seal). The sealing effect is created by the inherent pretension of the PTFE ring and the contact pressure of the O-ring. A total sealing pressure is created, which is increased as the system pressure rises. The static and dynamic coefficient of friction is almost the same. This ensures smooth movement without stick-slip even at low sliding speeds. Perfect start-up is ensured even after a longer standstill period. The static and dynamic coefficient of friction are almost the same. This ensures smooth movement without stick-slip even at low sliding speeds. Perfect start-up is ensured even after longer downtimes. The OHP profile has been replaced by the OEP profile.
Medium
all hydraulic fluids, e.g. water, mineral oils, water-oil emulsions, flame-retardant hydro-oils flammable hydro-oils, environmentally friendly pressure fluids (bio-oils), etc. (depending on the choice of O- Ring material)
Material
Standard materials:
- Seal ring: modified PTFE compound
- O-ring: NBR (alternatively FKM, EPDM, MVQ)
Advantages
- small, simple installation space
- good availability also in intermediate sizes for diameters up to 2,500 mm
- universal chemical resistance
- high temperature resistance
- good dry-running properties
- high extrusion safety
- low breakaway forces and sliding friction
- no stick-slip even at low speeds
- low abrasion
- Installation in closed installation spaces (> 30 mm piston diameter)
Installation instructions
To avoid damage to the seal, it must not be pulled over sharp edges. Normally, the OHP can be mounted in closed grooves from a diameter of 30 mm. The installation spaces must be carefully deburred and cleaned. The cylinder tubes must have lead-in chamfers. Excessive and uneven expansion of the PTFE ring must be avoided. When using piston rings up to 100 mm, the use of assembly aids is recommended. In special applications (high temperature, speed, specific pressure load or use in water, HFA, HFB fluids etc.) please contact our application engineering department.
Range of application
Mainly used in hydraulic and pneumatic valves, quick-closing cylinders, mobile hydraulics, machine tools, presses, agricultural machinery
