VANESSA Triple Offset Valves – Zero-Leakage Reliability for Critical Process Applications

VANESSA Triple Offset Valves 

Zero-Leakage Reliability for Critical Process Applications

VANESSA, a flagship valve brand under Emerson, represents over 50 years of engineering excellence in triple offset valve (TOV) technology. Designed for bidirectional zero leakage*, friction-free operation, and SIL 3 safety compliance, these valves are the preferred solution for severe service conditions in hydrocarbon storage, chemical processing, power generation, and emergency shutdown systems.

Key Technology Highlights

1. True Zero-Leakage Performance

   • Metal-to-metal torque sealing ensures bidirectional zero leakage (tested per ISO 5208, EN 12266-1 Leakage Rate A, and API 598 resilient seat standards), eliminating fugitive emissions.

   • Frictionless 90° rotation prevents seat wear, enabling long-term sealing integrity even after thousands of cycles.

2. Triple Offset Design for Lifetime Reliability

   • Eccentric 1: Axis offset behind the seal face for frictionless opening/closing.

   • Eccentric 2: Axis offset from valve centerline to enable smooth disc movement.

   • Eccentric 3: Conical seat angle倾斜优化 for automatic wedging action – the valve seals tighter as pressure increases.

   • No cavity design prevents media buildup, reducing contamination risks in slurries or corrosive fluids.

3. Built for Safety and Compliance

   • SIL 3 certified (IEC 61508) for emergency shutdown (ESD) systems in tank farms and hazardous environments.

   • Fire-safe per API 607/ISO 10497: Metal-sealed construction withstands extreme heat with zero leakage during fire events.

   • Emissions compliance: ISO 15848-1 BH certification for low fugitive emissions.

4. Low Maintenance and High Durability

   • Top-entry design allows in-line maintenance of disc, seat, and bearings without pipeline removal.

   • Extended MTBF (Mean Time Between Failures): No periodic seat replacements; only occasional gland packing adjustment may be needed.

   • Wide temperature range: Standard models from -29°C to +200°C; cryogenic/high-temperature variants available (-40°C to +600°C).

Applications – Trusted in Critical Industries

• Tank Farm ESD: First tank valve for crude oil, LNG, and volatile hydrocarbons (e.g., Vanessa 30,000 series).

• Chemical & Pharmaceutical: Corrosive media handling with API 598 zero-leakage assurance.

• Power Generation: Isolation in FGD systems, cooling water, and ash handling.

• Water & Wastewater: Abrasive slurry control with cavitation-resistant designs.

Technical Specifications

Why Choose VANESSA Triple Offset Valves?

• Proven Legacy: 300,000+ valves installed globally since the 1980s.

• Cost-Effective Lifespan: Reduced total cost of ownership (TCO) via minimal maintenance and no seat replacements.

• Dynamic Safety: Asymmetric disc design enables fail-close or fail-open functionality based on installation direction.

• Emerson Global Support: Technical service teams and distributors across 70+ countries.