The triple offset butterfly valve represents an advanced solution for fluid control in demanding and critical operating conditions. This technology is based on a three eccentricity structure that ensures metal to metal sealing without excessive friction, significantly extending the valve’s service life.
Technical Description
The triple offset butterfly valve—also known as a triple eccentric valve—features a stem offset from the X and Y axes of the valve centerline, generating a cam like motion during opening and closing.
This geometry eliminates premature contact between disc and seat, reducing wear and enabling a friction free operating cycle until the final point of closure.
Unlike the zero offset (concentric) butterfly valve—which rotates around the centerline with soft sealing and continuous friction—or the double offset version, which introduces partial cam action but still experiences initial rubbing, the triple offset design uses a 90° conical seat for contact only at the final sealing moment.
This makes it ideal for high pressure and high temperature applications, surpassing the limitations of earlier designs.
These valves excel where abrasive media, pressures above 150 psi, high temperatures, or fugitive emission sensitive services are present, such as oil & gas, refining, chemical processing, power generation, and pulp & paper industries.
They are preferred for steam, gas, or clean high temperature liquids, where metal seated designs—without soft overlays—offer both reliability and cost effectiveness.
Materials Table
| Element | Characteristics |
|---|---|
| Body Design | Long pattern, short pattern, top entry, welded body, flanged, lug, wafer, jacketed, cryogenic with extended stem |
| Material | Carbon steel, Duplex, Super Duplex, Stainless steel |
| Operating Temperature | Standard temperature |
| Pressure Class | ASME 150–600 / PN 10–64 |
| Seat / Sealing Type | Metal to metal, removable |
| Shut off Class | API 598, Class IV (FCI 70 3), Class V (FCI 70 2), Class VI (FCI 70 2), Zero Leakage |
| Standards | API 609, ASME B16.34 |
| DN Range | NPS 4 / DN 100 to NPS 96 / DN 2400 |
| Valve Type | Triple offset valve |
| Fugitive Emissions | Enhanced stuffing box to reduce fugitive emissions |
| Safety Integrity Level (SIL) | Inherently higher SIL design |
| Options | Bearing flushing for services like sulfur, steam jackets for heating in bitumen or liquid sulfur applications |
Triple offset butterfly valve
Triple offset butterfly valve with jacket
The design includes a field replaceable seat for rapid maintenance, customizable materials for body, disc, and sealing surfaces depending on process conditions, and ISO 5211 compliant mounting for electric, pneumatic, or hydraulic actuators.
Audco is ready to provide all information required to prepare a quick and complete quote.
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