Triple Offset Valves

Our Triple Offset Valve is A Premium Process Valve Made to the Highest Standards

Triple offset valves with minimum/zero maintenance requirements, represent the definitive solution for countless piping, process and instrumentation engineers around the world.

A virtually maintenance free valve that not only delivers uncompromising performance, but can provide a more efficient solution compared to ball, gate and plug valve designs.

How does a Triple Offset Valve work?

Triple Offset Design

The Vanessa Series 30,000 valve shares the same cone-to-cone principle with a globe valve, but sealing is performed by quarter turn rotation. TOVs use a sealing system consisting of a stationary seat and a rotating sealing surface sharing an identical shape: an inclined conic section. When these cones overlap, closed position is reached and sealing occurs. Such 'quarter turn globe' concept is made possible by the use of three 'offsets' meant to completely eliminate rubbing. Optimized seating angles and rotational characteristics guarantee superior tightness via an ingenious combination of the triple offset design and a flexible metal seal ring across all basic, cryogenic and high temperature configurations.

Offset 1

The shaft is placed behind the plane of the sealing surface to provide a continuous seat path.

Offset 2

The shaft is placed to one side of the pipe/valve centerline to allow the displacement of the seal from the seat during the 90° opening.

Offset 3

The seat and seal cone centerlines are inclined in respect to the pipe/valve centerline. This third offset completely eliminates rubbing.

Triple Offset Valve Configurations

Valve Construction

Series 30,000 is a robust valve capable of performing bidirectional zero leakage notwithstanding extreme temperature conditions. Indeed, its all-metal construction, inherently fire resistant, is unaffected by temperature changes and a fully integrated long bonnet keeps packing protected from extreme service temperatures (from -60 °C to 450 °C - from -76 °F to +842 °F).
Furthermore, the flange spot facing ensures flange bolting nut and washer planarity, increases reliability and safety of flanged joints with long term tightness and no re-tightening requirements.

Sealing components

The materials chosen for sealing, coupled with precise machining, significantly contribute to extending the life of the valve. Every Vanessa Series 30,000 valve in basic configuration features a smoothly grinded seat with Stellite^® grade 21 weld overlay highly resistant to galling, abrasion, erosion and corrosion.

The Vanessa seal ring is the key flexible component necessary to perform sealing and may be laminated in Duplex (as a minimum) or manufactured as a one-piece solid. Seal rings are easily interchangeable thanks to their self-centering ability and the presence of reference pins that simplify assembly. In addition, a dynamic spiral wound gasket ensures an adequate expansion and contraction of the seal ring during opening and closing.

Stellite^® is a registered trade name of Deloro

Applications for Triple Offset Valves

Vanessa has provided for decades an extremely reliable triple offset valve capable of delivering long-term positive isolation, on-off, flow control and emergency operations over a wide range of temperatures and pressure classes.