SEALING FOR ROTATING EQUIPMENT: Pressure seals
This type of seal allows axial and radial movements of rods/pistons simultaneously (like an Archimedes screw) and up to 350 bar pressure. Depending on their profile, rotary joints are either double-acting or single-acting.
Double-acting seals consist of a low-friction sealing ring and an O-ring as an exciting element and can be pressurised on both sides. However, single-acting rotary unions are spring energised lip seals.