Check-Flex G4-S Duckbill Check Valve

Level Invert for maximum drainage under gravity

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Vulcanised and reinforced like a tyre for durability

Flexible and wide seal

Flange drilling to match any mating flange

Sizes to fit all pipes

Encapsulated metal with strong single piece design for marine diffuser applications

Nominal Pipe Size

PVC DN100
Check-Flex G4-S0115
ID: 110mm L: 286mm H: 222mm W: 76mm

Twinwall DN100
Check-Flex G4-S0115
ID: 110mm L: 286mm H: 222mm W: 76mm

Ductile Iron DN100
Check-Flex G4-S0115
ID: 118mm L: 286mm H: 222mm W: 76mm

Polyethylene DN100
Check-Flex G4-S0115
ID: 110mm L: 286mm H: 222mm W: 76mm
Check-Flex G3-S01--
ID: S01--mm L: 393mm H: 268mm W: 102mm
PVC DN150
Check-Flex G4-S0160
ID: 160mm L: 384mm H: 378mm W: 102mm

Twinwall DN150
Check-Flex G4-S0180
ID: 180mm L: 384mm H: 378mm W: 102mm

Ductile Iron DN150
Check-Flex G4-S0180+G
ID: 170mm L: 384mm H: 378mm W: 102mm

Polyethylene DN150
Check-Flex G4-S0160
ID: 160mm L: 384mm H: 378mm W: 102mm

Clay DN150
Check-Flex G4-S0180
ID: 178mm L: 384mm H: 378mm W: 102mm
Polyethylene DN175
Check-Flex G4-S0180
ID: 180mm L: 384mm H: 378mm W: 102mm
PVC DN200
Check-Flex G4-S0200
ID: 200mm L: 405mm H: 454mm W: 102mm

Ductile Iron DN200
Check-Flex G4-S0230
ID: 222mm L: 405mm H: 454mm W: 102mm

Polyethylene DN200
Check-Flex G4-S0200
ID: 200mm L: 405mm H: 454mm W: 102mm
PVC DN225
Check-Flex G4-S0250
ID: 245mm L: 497mm H: 518mm W: 102mm

Twinwall DN225
Check-Flex G4-S0267
ID: 267mm L: 497mm H: 518mm W: 102mm

Clay DN225
Check-Flex G4-S0267
ID: 263mm L: 497mm H: 518mm W: 102mm
Ductile Iron DN250
Check-Flex G4-S0278
ID: 278mm L: 497mm H: 518mm W: 102mm

Polyethylene DN250
Check-Flex G4-S0250
ID: 250mm L: 497mm H: 518mm W: 102mm
PVC DN300
Check-Flex G4-S0328+G
ID: 315mm L: 627mm H: 608mm W: 152mm

Twinwall DN300
Check-Flex G4-S0345
ID: 345mm L: 627mm H: 608mm W: 152mm

Ductile Iron DN300
Check-Flex G4-S0328
ID: 328mm L: 627mm H: 608mm W: 152mm

Polyethylene DN300
Check-Flex G4-S0328+G
ID: 315mm L: 627mm H: 608mm W: 152mm

Clay DN300
Check-Flex G4-S0355
ID: 355mm L: 662mm H: 678mm W: 152mm
PVC DN350
Check-Flex G4-S0355
ID: 355mm L: 662mm H: 678mm W: 152mm

Ductile Iron DN350
Check-Flex G4-S0380
ID: 380mm L: 662mm H: 678mm W: 152mm

Polyethylene DN350
Check-Flex G4-S0355
ID: 355mm L: 662mm H: 678mm W: 152mm
Twinwall DN375
Check-Flex G4-S0435
ID: 435mm L: 727mm H: 788mm W: 152mm
PVC DN400
Check-Flex G4-S0410
ID: 400mm L: 727mm H: 788mm W: 152mm

Ductile Iron DN400
Check-Flex G4-S0435
ID: 429mm L: 727mm H: 788mm W: 152mm

Polyethylene DN400
Check-Flex G4-S0434+G
ID: 400mm L: 727mm H: 788mm W: 152mm
Twinwall DN450
Check-Flex G4-S0510
ID: 510mm L: 913mm H: 958mm W: 203mm

Ductile Iron DN450
Check-Flex G4-S0490
ID: 490mm L: 817mm H: 838mm W: 152mm
Ductile Iron DN500
Check-Flex G4-S0540
ID: 532mm L: 913mm H: 958mm W: 203mm

Polyethylene DN500
Check-Flex G4-S0510
ID: 500mm L: 913mm H: 958mm W: 203mm
Twinwall DN600
Check-Flex G4-S0680
ID: 680mm L: 1048mm H: 1096mm W: 203mm

Polyethylene DN500
Check-Flex G4-S0510
ID: 500mm L: 913mm H: 958mm W: 203mm
Ductile Iron DN700
Check-Flex G4-S0740
ID: 740mm L: 1178mm H: 1339mm W: 203mm
Ductile Iron DN800
Check-Flex G4-S0840
ID: 842mm L: 1354mm H: 1384mm W: 254mm
Ductile Iron DN900
Check-Flex G4-S0940
ID: 945mm L: 1574mm H: 1690mm W: 254mm
Ductile Iron DN1000
Check-Flex G4-S1050
ID: 1050mm L: 1654mm H: 1766mm W: 254mm
Check-Flex G4-S12--
Built To Order Valves
Specify Pipe Outside Diameter
Built To Order Valves
Specify Pipe Outside Diameter
Table displaying model, style, pipe size range, and pipe connection options for various products.

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ModelStylePipe Size RangePipe Connection
-S-C-W-F / -Fi / -Fd-G
G5Inline Fabricated80–3000mm----
G5MInline Moulded100–150mm-
G5-RESIInline EN13564-180–200mm-
G4Duckbill Fabricated100–2400mm-----
G3Duckbill Fabricated100–2400mm-----
G3MDuckbill Moulded100–150mm-
G2Inline Duckbill Fabricated50–300mm-