Restrained Universal Coupling MAXIGRIP Ductile Iron DN50-DN400

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The MAXIGRIP restrained universal coupling is an engineered piping solution designed to join plain-ended pipes of identical or differing outer diameters while providing full end-load restraint against tensile pull-out forces. Manufactured from high-grade EN-GJS-500-7 ductile iron, this wide-tolerance fitting bridges transitions across diverse piping materials, including ductile iron, cast iron, carbon steel, PEHD (PE80/PE100), PVC-U, and asbestos cement. By combining hydraulic sealing with independent mechanical gripping teeth, MAXIGRIP eliminates the necessity for dedicated concrete thrust blocks in pressurized distribution lines, significantly speeding up trench assembly and rehabilitation operations.

Corrosion protection is provided by an electrostatic powder epoxy coating applied to a minimum layer thickness of 250 μm in RAL 5015 blue, certified for drinking water applications. The sealing arrangement utilizes drinking-water-approved EPDM elastomer profiles conforming to EN 681-1, which deliver dependable tightness under working pressures up to PN16. The coupling accommodates angular deflections of up to 4 degrees across the joint, absorbing soil settlements, ground movement, and minor installation misalignments without sacrificing joint integrity or pressure retention.

Engineered for straightforward site handling, the universal coupling allows installation directly over pipe ends without requiring pre-assembly dismantling. Standardized stainless steel fasteners enable independent progressive torque application on each side, ensuring optimal gasket compression and progressive grip engagement across nominal diameters from DN 50 (46–70 mm range) through DN 400 (390–430 mm range). It provides a versatile, durable, and low-maintenance connection for potable water networks, industrial process piping, and municipal utility systems.