The Eccentric Butterfly Valve (available in Double Offset or Triple Offset design) represents the premium tier of butterfly valve technology. In a standard concentric butterfly valve, the disc rubs against the seat through the entire 90° rotation, causing wear. In an offset design, the stem is positioned behind the disc centerline (double offset) or also behind the seat centerline (triple offset). This creates a “cam action” — the disc only contacts the seat during the final 1-2° of closure. At all other angles, the disc is completely free from seat contact. This drastically reduces friction, extends seat life, and allows for metal-to-metal seating. Triple offset valves are fire-safe and can achieve zero leakage even with metal seats, making them suitable for steam, high-temperature oils, and cryogenic services.
Why Choose Us / Advantage
Zero Leakage (TOV): ISO 5208 Rate A with metal seat — no soft elastomers required.
Fire Safe Certified: API 607 or ISO 10497 for critical applications.
High Cycle Life: Rated for 50,000+ cycles without performance loss.
Wide Temperature Range: -196°C (cryogenic) up to +600°C (steam).
Custom Materials: Seat and disc available with Stellite hardening.
Technical Data
★ Specification DOV (Double Offset) TOV (Triple Offset)
★ Body Ductile Iron / WCB / SS316 Ductile Iron / WCB / SS316
★ Seat PTFE / RTFE Metal + Graphite
★ Disc SS304 / SS316 SS304 / SS316 / Hardened
★ Pressure PN16 / Class 150 PN25 / Class 150-300
★ Temp Range -20°C to +200°C -196°C to +600°C
★ Leakage Rate Zero Zero (ISO 5208 Rate A)
Applications
● Steam distribution lines
● High temperature oil and thermal fluid
● Cryogenic applications (LNG, liquid nitrogen)
● Refinery and petrochemical processes
● Abrasive slurry services
