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Viking Johnson FlexCheck - Model 661 -Valve
Its simple, yet ingenious, design features a precision moulded fully-encapsulated steel disc, incorporating nylon reinforcement in the flex hinge. The ‘O’ ring profile seat face ensures a bubble-tight shut-off, preventing back flow at high and low working pressures. The seating surface is at a 45 degree angle, moderating disc travel and permitting optimum flow rates. The disc’s resulting 35 degree stroke is less than half the typical 80 or 90 degrees of a traditional swing check valve. Combine this with its flexible action and this results in significantly reduced valve closing time, flow reversal and both slam and ‘water hammer’ effects. All this enables installations in far more varied applications than traditional swing check valves. Close coupling to pumps, tees, other valves or accessories is also not a problem for this versatile product.
Developed primarily for use in water and wastewater applications, the FlexCheck valve is engineered to deliver dependable, maintenance-free performance over extended periods. Manufactured from durable ductile iron, the unit comprises only three parts: body, bonnet and disc. The absence of moving parts minimises the risk of clogging and maximises operational reliability. Standard features include 100% full-flow area and an epoxylined interior. A rubber-lined version is also available, ideal for the conveyance of abrasive or corrosive fluids. FlexCheck is suitable for installation in horizontal or vertical pipes (flow must be upwards in vertical installations). Its in-built durability is demonstrated through an independent rigorous 1,000,000 continuous cycle test. FlexCheck is supplied drilled and tapped for installation of the optional back-flushing device, commonly used for priming, backflushing, draining and system testing. The FlexCheck is the perfect solution to noise, water hammer and high maintenance.
- Ductile iron body and bonnet – for durability and reduced weight
- Fully moulded disk assembly – ‘O’ Ring profile seat ensures tight shut off
- Nylon reinforced hinge – provides extended operating performance
- Temperature rating: (Nitrile) 0°C to 90°C (EPDM) 10°C to 90°C
- External backflush device (DN50 - DN600) – optional inclusion for system priming or flushing
- Rubber lining (DN80 - DN600) – optional inclusion for abrasive media
- Flange drillings: PN10, PN16, ANSI
Body & Cover
The FlexCheck valve body and cover is EN 1563: EN JS 1040 ductile iron for increased durability. Flanges are available drilled PN10, PN16 or ANSI B16.1 Class 125
Rubber Lining- Optional
Lining of internal surfaces will extend product life where the media is either erosive or corrosive
Door/Disc
Fully moulded door incorporating a steel disc for rigidity and nylon reinforcement in the hinge area that enhances flexibility and operating performance
Interchangeable
The face to face dimensions on most FlexCheck valves are identical to BS5153 face to face dimensions, which enables fitting without pipeline modification
Installation
Can be installed in horizontal or vertical pipelines (flow must be upwards) and in close proximity to pumps where space is a premium
Virtually Maintenance Free
As the FlexCheck has only one moving part and no bearings, pivot pins, mechanical hinges, linkages, mechanisms or packing, its simplicity in design and operation ensures minimal maintenance
