ASTM A216 WCB Butterfly Valve, 8 Inches, Double Offset, Lug

Product Name: ASTM A216 WCB Butterfly Valves
Type: Double Offset Butterfly Valve
Body Material: ASTM A216 WCB, Cast Carbon Steel
Size: 8 Inch, DN200, 200 mm
Pressure: Class 150 LB, PN20
End Connection: Lug Ends
Operation: Gear Operated
Medium: Water, Oil, Gas, etc
Temperature Range: -29°C to 150°C

This Double Offset Butterfly Valve has been successfully applied in demanding and extreme services, including high-temperature applications, throttling steam control, polymerizing media, liquor services with entrained solids, high-cycle industrial gas duty, process gas shut-off, paper stock isolation, vacuum pump isolation, corrosive chemical service, fire-safe refinery and chemical applications, heat-transfer service, and hydrocarbon throttling service.

Technical Specification

» Normal Size Range:
   Class 150 LB: 2-60 Inch
   Class 300 LB: 2-48 Inch
   Class 600 LB: 2-24 Inch
» Normal Pressure Rating: Class 150-600 LB, PN10–PN40, 10K–20K
» Body Connection: Wafer type, Lug Type, Double Flange
» Body Material: Carbon Steel, Stainless Steel, Duplex Steel, Nickel Aluminum Bronze, Hastelloy
» Disc Material: Stainless Steel, Duplex Steel, Nickel Aluminum Bronze, Monel
» Stem Material: 17-4PH, SS 316, Duplex Steel, Hastelloy, Titanium Alloys
» Seat Material: PTFE or RTFE with Resilient Energizer
» Packing Material: PTFE
» Shutoff Rating: Class VI, Bubble Tight
» Design Standard: ASME B16.34, ASME VIII, API 609, MSS SP-68, EN 593, EN 12516
» Certifications: API 607, PED
» Shell/Seat Test: API 598
» Face to Face: API 609, ISO 5752
» Manual Operator: Bare Shaft, Lever Handle, Worm Gear Operator
» Automatic Operation: Pneumatic Actuator, Electric Motor
» Temperature Range: Soft Seat: -29°C to 150°C
» Medium: water, gas, oil, etc

Application Scope

» Chemical and Petrochemical Industries
» Liquefied Gas and Refrigeration Systems
» Heavy Industrial Applications
» Power Generation and Co-Generation Plants
» Steel and Iron Works
» Commercial and Industrial Facilities
» Pulp and Paper Mills
» Oil Refineries and Oilfield Operations
» Shipbuilding and Marine Industries
» Hydrocarbon Processing and Gas Piping Systems
» Local and District Energy Supply Systems
» Construction and Infrastructure Projects

Double Offset Butterfly Valve

The Double Offset High-Performance Butterfly Valve is a new type of butterfly valve designed by absorbing the advantages of several different structural butterfly valves. The sealing surface of the valve plate is a spherical arc surface. The sealing mechanism achieves a true dynamic seal through system pressure, thus providing reliable sealing performance and durability. It features a small volume, light weight, wide manufacturing range, and is easy to maintain and repair. Due to its double offset butterfly plate design and single-piece flexible lip-shaped sealing seat, it is ideal for applications requiring reliable sealing and good regulating characteristics. It can be used for quick shut-off or regulating flow.

Double Offset Frictionless Design

• 1st offset: Shaft is positioned downstream from the centerline of the seat.
• 2nd offset: Shaft is off center from the vertical axis of the seat.
• ISO 5211 Top Flange
• In addition to standard, durable V-ring packing, you can also choose from optional graphite
• high temperature packing or emissions control packing.
• Bi-Directional, Shut off performance
• Seat Options: Rubber, PTFE, RPTFE, or Fire Safe PTFE
• The double offset operating principle minimizes seat wear and lowers operating torque to
• improve durability.
• Positive sealing is mechanically achieved and does not rely on line pressure assistance.

Seat Structure

Double Offset PTFE Seat Butterfly Valve

• A surplus of material between the PTFE Seat and Disc ensures a reliable seal in a low pressure environment.
• In high pressure situations, the force of the medium pushes against the seat contacting the sealing surface for a stronger seal.
• The disc surface has a conical design to reduce frictional force. The valve seat can also be replaced or repaired easily.

Double Offset Fire Safe PTFE Butterfly Valve

• Fire Safe valve seat with dual seal includes a primary PTFE seat insert and metal seat. 
• In the event that the PTFE insert is destroyed, the secondary metal seat provides an effective shut-off. 

Shaft Retention

• Externally retained, double blowout proof stem design as API 609
• External: Shaft is designed with an integral collar and gland follower to prevent blowouts.

Zero Leakage

• Disc-Seat sealing is achieved by evenly loading torque force onto the disc's laminated seal

ISO 5211 Top Mounting

Different End Connections Available: