Triple Offset Butterfly Valves (TOV) for Critical Isolation & Control
Zero-leakage metal-to-metal sealing.
Engineered for high-performance service in Energy, LNG, Refining, Petrochemical, Marine, and Chemical industries.
High-Performance Triple Offset Butterfly Valves for Demanding Industrial Applications
NordenFlow Triple-Offset Butterfly Valves (TOV) are engineered for critical applications where zero-leakage and long-term reliability are non-negotiable. Unlike standard butterfly valves, our TOBV series features a unique 3-way eccentric geometry that eliminates friction between the seal and seat throughout the entire 90-degree stroke, only making contact at the final point of closure
Leveraging precision-engineered triple eccentric geometry and a durable metal-to-metal seal design, our Triple Offset Butterfly Valves deliver certified zero-leakage performance. This allows for critical isolation and reliable control, even under severe operating conditions, including extreme temperature, high pressure, or highly corrosive media.
Compared to traditional gate and globe valves, TOVs offer a superior package for modern process industries. Benefits include higher flow capacity at lower weight, faster actuation speeds, reduced torque requirements, and a significantly lower overall lifecycle cost—making them the preferred choice for reliable, low-maintenance isolation and shut-off service.
Whether used for critical shut-off, throttling, fugitive emission control, or fire-safe applications, Nordenflow TOVs maintain sealing integrity and long-term stability.
How Triple Offset Geometry Ensures Zero Leakage
- First offset: The stem is positioned behind the disc centerline, reducing friction and eliminating seal wear during opening and closing
- Second offset: The stem is located off the pipeline centerline, enabling smooth, cam-like motion of the disc
- 3rd offset: The sealing surface is machined into a conical profile.
This creates a torque-seated, frictionless metal-to-metal seal with no rubbing, guaranteeing long service life and bubble-tight shutoff.
Technical Highlights
- Sizes: DN80 – DN1200
- Pressure classes: PN16 – PN420 / ANSI 150 – 900
- Design: triple eccentric geometry, metal-to-metal seat
- Materials: carbon steel, stainless steel, duplex, super duplex
- Seal ring: laminated metal + graphite or stainless steel
- Leakage class: API 598 / ISO 5208 / Class VI (bubble-tight)
- Actuation: pneumatic, hydraulic, or electric
- End Connection: Flanged, Lug, Wafer Buttweld
- Design Standard: API 609, ASME B16.34
- Testing Standard: ISO 5208, EN12266-1, API 6D, API 598, BS 6755
- Certifications: ATEX, SIL2, PED
- Temperature Range: Capable of handling extreme thermal cycling from cryogenic service (-196°C) to high-temperature steam and exhaust gases (+600°C)
Key Advantages for Industrial Operators:
- Zero-leakage metal-to-metal sealing
Ideal for critical isolation in high-pressure and hazardous service environments. - Fire-safe and fugitive emission compliant
Engineered to minimize leakage to atmosphere and meet strict safety standards - Compact and lightweight
Reduces installation cost, piping stress, and actuator sizing requirements. - High durability under severe conditions
The friction-free triple-offset design ensures long seal life, even in cyclic operations. - Lower total cost of ownership
Minimal maintenance, lower torque, and long-term stable sealing reduce lifecycle expenses. - Suitable for throttling and on/off control
Performance remains stable across a wide range of operating conditions.
Why Choose Nordenflow Triple Offset Butterfly Valves
Nordenflow ensures the entire shutdown and control package is engineered for reliability and compliance:
– Actuator sizing and torque calculation
– Pneumatic, electric, and hydraulic actuation packages
– SIL/ATEX compliant configurations
– Local engineering support and technical consulting
– Full documentation, FAT support, and lifecycle service
Comparison for High-Pressure Decisions:
| Feature | Double-Offset (High Performance) | Triple-Offset (Severe Service) |
| Sealing Type | Friction during stroke | Frictionless (Cam-action) |
| Seat Material | PTFE / RTFE / Metal | Laminated Metal / Solid Stellite |
| Leakage Class | Class VI (Soft) / Class IV (Metal) | Zero-Leakage (Bubble-tight) |
| Best For | Water, HVAC, Light Chemicals | Steam, Crude Oil, High-Temp Gas |
Our in-house engineering support guarantees your TOV solution is accurately sized, certified, and installed for long-term operational success. For complete valve packages, explore our full range of applications and Actuator Selection Guides on our Actuators page.