Description
Crane F646G / F641G / F656G / F651G / F676G / F671G Butterfly Valves
Semi-Lugged Wafer Pattern Gearbox Operated Butterfly Valves – Ductile Iron
The Crane Fluid Systems F646G, F641G, F656G, F651G, F676G and F671G series is a range of semi-lugged wafer pattern, gearbox-operated butterfly valves designed for reliable quarter-turn isolation in HVAC, water distribution, heating, cooling and general building-services applications.
The valves are available from 50 mm to 600 mm and have a PN16 / ANSI Class 125 pressure rating. Their universal pattern makes them compatible with both BS EN 1092-2 PN16 and ANSI B16.1 Class 125 flanges. The range uses a ductile iron body and offers different disc and seat-liner materials for selection according to the service conditions.
Key Features
- Semi-lugged wafer pattern design
- Gearbox and handwheel operated
- Size range: 50–600 mm
- Pressure rating: PN16 / ANSI Class 125
- Universal flange pattern
- Compatible with BS EN 1092-2 PN16 flanges
- Compatible with ANSI B16.1 Class 125 flanges
- Ductile iron body
- Ductile iron, stainless steel and aluminium bronze disc options
- EPDM and nitrile seat-liner options
- 420 stainless steel shafts
- Designed to BS EN 593
- BIM files available.
Semi-Lugged Wafer Pattern Design
The F646G series combines a compact wafer-pattern butterfly valve with a semi-lugged body configuration.
Its universal pattern allows installation with either BS EN 1092-2 PN16 or ANSI B16.1 Class 125 flanges. This makes the valve suitable for projects where European and North American flange standards need to be accommodated.
The wafer-style construction also provides a compact installation compared with many conventional flanged isolation valves, making it particularly useful in mechanical rooms and plant spaces.
Gearbox Operation
The F646G series uses a gearbox with handwheel operation rather than a direct lever.
This configuration is particularly advantageous for larger valve sizes, where the operating torque can make direct manual operation difficult.
The gearbox provides:
- Reduced manual operating effort
- Controlled opening and closing
- Precise valve positioning
- Easier operation of large-diameter valves
- Clear visual indication of valve position
Crane Fluid Systems offers its butterfly valves in both lever- and gearbox-operated configurations, depending on valve size and application.
Durable Ductile Iron Construction
The F646G series uses a ductile iron body, providing a robust construction for water, HVAC and building-services applications.
The product family offers several disc material options:
- Ductile Iron
- Stainless Steel
- Aluminium Bronze
This allows the valve configuration to be selected according to the operating medium, corrosion conditions and project requirements.
EPDM and Nitrile Seat Options
The F646G family is available with EPDM and nitrile seat liners.
EPDM
EPDM is commonly selected for water-based applications such as:
- Chilled water
- Heating water
- Cooling water
- General water distribution
Nitrile
Nitrile provides an alternative liner material for applications where its particular resistance characteristics are required.
The correct liner should always be selected according to the actual fluid, temperature and operating conditions.
420 Stainless Steel Shaft
The valves incorporate 420 stainless steel shafts for increased mechanical strength.
The shaft transfers operating torque from the gearbox to the butterfly disc and is designed to provide reliable performance during repeated quarter-turn operation.
Typical Applications
The Crane F646G series is suitable for:
- HVAC systems
- Chilled water systems
- Heating water systems
- Cooling water systems
- Commercial buildings
- Industrial water systems
- Pumping systems
- Water distribution
- Mechanical plant rooms
- District heating and cooling
- General building services
- Industrial utilities
Crane’s butterfly valve range is intended for quarter-turn isolation and is available in wafer and lugged configurations with lever or gearbox operation.
Technical Specifications
| Specification | Details |
|---|---|
| Brand | Crane Fluid Systems |
| Model Series | F646G / F641G / F656G / F651G / F676G / F671G |
| Product Type | Butterfly Valve |
| Design | Semi-Lugged Wafer Pattern |
| Operation | Gearbox Operated |
| Size Range | 50–600 mm |
| Pressure Rating | PN16 / ANSI Class 125 |
| Body Material | Ductile Iron |
| Disc Options | Ductile Iron / Stainless Steel / Aluminium Bronze |
| Seat Liner | EPDM / Nitrile |
| Shaft Material | 420 Stainless Steel |
| Flange Compatibility | BS EN 1092-2 PN16 / ANSI B16.1 Class 125 |
| Valve Standard | BS EN 593 |
| Operation | Quarter Turn |
| BIM | Available |
The manufacturer advises referring to the product datasheet for complete technical and dimensional information.
Product Attributes
| Attribute | Value |
|---|---|
| Brand | Crane Fluid Systems |
| Model | F646G / F641G / F656G / F651G / F676G / F671G |
| Product Type | Butterfly Valve |
| Valve Design | Semi-Lugged Wafer Pattern |
| Valve Function | Isolation |
| Operation | Gearbox Operated |
| Nominal Size | 50–600 mm |
| Pressure Rating | PN16 / ANSI Class 125 |
| Body Material | Ductile Iron |
| Disc Material | Ductile Iron / Stainless Steel / Aluminium Bronze |
| Seat Material | EPDM / Nitrile |
| Shaft Material | 420 Stainless Steel |
| Connection | Wafer / Universal Pattern |
| Flange Standard | BS EN 1092-2 PN16 / ANSI B16.1 Class 125 |
| Design Standard | BS EN 593 |
| Applications | HVAC, Water, Heating & Cooling |
Why Choose the Crane F646G Series?
The Crane F646G / F641G / F656G / F651G / F676G / F671G series provides a practical solution for projects requiring large-diameter, semi-lugged wafer butterfly valves with gearbox operation.
Its combination of a ductile iron body, 420 stainless steel shaft, multiple disc materials and EPDM or nitrile seat options provides flexibility for different water and building-services applications. The PN16 / ANSI Class 125 universal patternis especially useful for projects requiring compatibility with either European or North American flange standards.
With sizes extending to 600 mm, the F646G series is particularly suitable for larger HVAC distribution networks, central plant rooms, water systems and industrial utility pipework.
Crane also provides the relevant datasheet, installation/operating/maintenance documentation and BIM resourcesfor the series.
