Triple Offset Butterfly Valve

Technical Summary

Nominal Size: 2” to 60”

Pressure Class: Class 150 to Class 1500

Temperature Range: -196°C to 650°C

Design Standards: API 609 (Category B), ASME B16.34

Face to Face: API 609, ASME B16.10

End Connections: Flanged / Butt Weld / Wafer / Lug

Inspection and Testing: API 598

Construction and Materials

Body and Pressure Retaining Parts

• Carbon Steel
• Stainless Steel
• Alloy Steel
• Duplex Stainless Steel
• Super Duplex Stainless Steel

Internal Components

• Disc: Stainless Steel / Duplex / Alloy Steel
• Stem: Stainless Steel / Alloy Steel
• Seat: Metal seated with laminated seal ring (Stainless Steel + Graphite)

Sealing System

• Seat Design: Metal-to-metal sealing with laminated seal ring
• Seal Ring: Multi-layer stainless steel with graphite or metallic sealing elements
• Packing: Graphite packing for high temperature service
• Gasket: Spiral wound gasket with graphite filler

Functional Design

Triple Offset Butterfly Valve incorporates three offsets that eliminate friction between the disc and seat during operation. The disc engages the seat only at the final stage of closure, reducing wear and ensuring long service life.

The metal seated design enables bi-directional sealing with tight shut-off performance under high pressure and high temperature conditions. This makes the valve suitable for critical isolation applications where resilient seated valves are not suitable.

Material and Grade

Standard Materials

Component	Material	Grade	Typical Application
Body	Carbon Steel	ASTM A216 WCB	General industrial and high pressure service
Body	Stainless Steel	ASTM A351 CF8 / CF8M	Corrosive and high temperature environments
Body	Alloy Steel	ASTM A217 WC6 / WC9	High temperature steam and power applications
Disc	Stainless Steel	ASTM A351 CF8M / SS316	Corrosion resistance and sealing performance
Disc	Duplex Stainless Steel	ASTM A890 F51	High strength and chloride resistance
Stem	Stainless Steel	ASTM A182 F316 / F6a	Strength and wear resistance
Seat	Stainless Steel with laminated seal ring	Metal seated	Zero leakage and high temperature sealing

Extended Materials (On Request)

• Super Duplex Stainless Steel (F53 / F55) for offshore and aggressive environments
• Alloy 20 for acidic chemical service
• Hastelloy C276 for highly corrosive applications
• Inconel 625 for extreme temperature and pressure service

Additional Information

Valve Type	Triple Offset Butterfly Valve
Operation	Manual / Gear Operated / Electric Actuated / Pneumatic Actuated
Design Feature	Triple offset geometry eliminating seat friction
Flow Characteristics	Quarter-turn operation with tight shut-off
Leakage Control	Bi-directional tight shut-off
Seat Design	Metal seated
Service Conditions	High pressure and high temperature applications

End Connections

• Flanged as per ASME B16.5
• Butt weld as per ASME B16.25
• Wafer type installation between flanges
• Lug type configuration for bolted installation

Applications

• Oil and gas industry: high pressure pipeline isolation and process systems
• Power generation: steam lines, turbine bypass, and high temperature service
• Petrochemical and refining: critical isolation in high temperature process units
• Mining and metals: abrasive and high temperature service lines
• Marine and offshore: high performance isolation in harsh environments
• Water and desalination: large diameter high performance isolation systems