DAS stands for Double‑Acting Seal and refers to a hydraulic seal engineered to deliver high sealing performance in both directions. Built from durable compounds such as nitrile rubber (NBR) or polyurethane (PU), these seals are available in various shapes and sizes to fit different grooves. Consequently, DAS hydraulic seals maintain integrity during bidirectional motion and pressure.

Commonly used in hydraulic cylinders and other hydraulic components, these seals withstand high pressures, elevated temperatures, and fast reciprocating speeds in both extension and retraction. Moreover, they perform reliably where dirt, dust, and other contaminants are present. As a result, they suit harsh and demanding environments.

Technical Specifications

• Materials: Nitrile rubber (NBR) or polyurethane (PU)
• Temperature range: −40°C to +100°C (−40°F to +212°F)
• Pressure range: 0 to 50 MPa (0 to 7,250 psi)
• Speed: Up to 20 m/s (66 ft/s)

Typical Applications in Construction Machinery

• Excavators
• Bulldozers
• Backhoes
• Wheel loaders
• Skid steer loaders
• Cranes
• Concrete mixers
• Asphalt pavers

Key Benefits

• Excellent sealing performance in both directions
• High wear resistance and durability
• Suitable for a wide range of hydraulic applications
• Long service life with reduced maintenance

Overall, DAS hydraulic seals provide a reliable and cost‑effective way to protect hydraulic systems in construction machinery from leaks and contamination. In addition, their bidirectional sealing capability makes them especially well‑suited to applications with harsh operating conditions.