The innovative design incorporates two special grooves in the D-shaped profile of the seal to sustain an oil film for sufficient lubrication of the seal against its counter surface, ensuring adequate friction.
The compact double-acting piston seal, which has been subjected to extensive laboratory testing and long-term field testing in monitored applications, was developed in response to increasing demands from high-pressure hydraulic applications. Machines, equipment and motors are now being fitted with more powerful hydraulic cylinders, meaning the hydraulics are subject to higher pressures and temperatures.
The seal is manufactured from Zurcon® Z13 polyurethane (PU) material, which has been specially developed to cope with pressures of up to 500 bar/ 7,250 psi at both sides of the seal and at temperatures up to +120°C / +248°F. This gives the seal long life, even under demanding conditions. Offering superb mechanical and elastic properties, the seal loses none of its resilience over time and can be used in cylinders with lower quality inner walls.
Talking about this development, Andrew Longdon, UK Technical Manager at Trelleborg Sealing Solutions, says: "We have made subtle but significant changes to our previous Glyd Ring® compact double-acting piston seal, leading to a new and improved best-in-class seal for hydraulic cylinders with the ability to thrive in unforgiving conditions.
"In the latest more powerful hydraulic applications, high pressure is combined with elevated temperatures. Our new Zurcon® Z13 PU material used in Zurcon® Glyd Ring® D is specially developed to cope with this combination.
"We can now offer a seal for hydraulic cylinders that has a long life – this advanced solution has leapfrogged the competition."
The pioneering seal was a joint development between Trelleborg's research and development centre in Stuttgart, Germany, and their Polyurethane Centre of Excellence in Livorno, Italy.
Core industrial application areas for Zurcon® Z13 Glyd Ring® D include construction machinery, earthmoving equipment, mobile cranes, forklift trucks and any other solutions involving mobile hydraulics. The seal offers superior resilience and good friction properties. It is compatible with hydraulic, mineral, synthetic and water-based fluids and with a hardness of 60 shore D offers outstanding wear resistance, excellent extrusion properties and hydrolysis resistance.