A problem on some tandem seal arrangements used in hydraulic cylinders is pressure build-up between the seals. As a solution to this, Trelleborg Sealing Solutions introduces Turcon® Stepseal® V. Its innovative technology, incorporating a number of patented and unique features, prevents pressure being trapped even in the most difficult of arrangements.
Requirements for sealing are varied and difficult in hydraulic cylinders
In hydraulic cylinders, used in everything from precise positioning equipment in machine tools to heavy earth moving machinery in the toughest working environments, the requirements for sealing are varied and difficult. The applications are dynamic, often operating at high speeds and significant pressures. A single seal is rarely a good enough solution and in most cases, a configuration of seals is required.
Typically, to optimize sealing integrity a cylinder will include between three and five different dynamic seal and scraper types, some in tandem arrangement. Though configurations that use Turcon® Stepseal® are usually effective, in some designs, pressure can still build up between two seals. Based on their experience in hydraulic applications, engineers at Trelleborg Sealing Solutions looked for an even more effective geometry for these exceptional situations. The result is Turcon® Stepseal® V.
Picture shows Turcon® Stepseal® V
Turcon® Stepseal® V is engineered to prevent pressure build-up in even the most difficult of hydraulic sealing arrangements
Turcon® Stepseal® V incorporates a number of unique features. These include a patented hydrostatic pressure relief system, which provides rapid pressure actuation and pressure balancing under all service conditions. A machined valve groove ensures precise opening and closing of the relief channel, providing robust performance of the relief function independent of hardware deflection.
The inherent excellent friction characteristics, wear and abrasion resistance of Turcon®, the Trelleborg Sealing Solutions proprietary PTFE based material, is enhanced with Stepseal® V’s contoured rear chamfer for hydrodynamic back-pumping. In back-pumping technology, on the forward stroke of the shaft, an oil lubricating film is distributed under the seal. On the return stroke, the oil is back-pumped into the system, preventing leakage, reducing dynamic friction and breakaway force, even after extended periods of rest.
Picture shows a typical hydraulic sealing arrangement including Turcon® Stepseal® V
A seal with overall excellent performance and allowing easy installation
Performing over a wide temperature range from -45°C to 200°C/ -49°F to 392°F, Turcon® Stepseal® V is suitable in both static and especially dynamic situations. It operates at speeds up to 15 m/s /49 ft/sec with reciprocating movements and frequencies up to 5 Hz in pressures up to 80 MPa/ 800 bar/ 11600 psi. With excellent compatibility to media including many commonly encountered hydraulic fluids such as those based on mineral oil, flame retardant compounds, environmentally safe fluids (bio-oils) and water. In addition, the design and function of the seal means no buffer volume is required, saving both cost and space.
Easy to install the Turcon® Stepseal® V design has a stabilizing edge which prevents seal deformation and increases assembly robustness by protecting the seal face during rod insertion. It can be fitted in bore diameters up to 2700 mm /8’10’’ and rod diameters up to 2600 mm/ 8’ 6’’. With very good extrusion resistance, it suits wide hardware clearances.
Turcon® Stepseal® V provides significantly extended life and a superior overall performance
“Trelleborg Sealing Solutions is the leading supplier of seals to the hydraulic sector in Europe,” says Jan Winther, European Segment Director Fluid Power. “This has allowed us to continually advance the technology of products for this industry. Turcon® Stepseal® V represents a major innovation focused on the specific issue of pressure build-up in some tandem seal arrangements. In these situations it provides significantly extended life and a superior overall performance.”