Check-Flex G4-G Duckbill Check Valve

Metal backplate mounted G4 valve to suit site conditions

Explore the 3D model!
Drag to rotate, scroll to zoom, and click the hotspots to discover more.

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

Check-Flex G4-G0100
ID: 104 L: 276 H2: 225
W: 200 H: 200
Anchors: 4x M12
Check-Flex G4-G0150
ID: 154 L: 326 H2: 380
W: 250 H: 250
Anchors: 4x M12
Check-Flex G4-G0200
ID: 205 L: 359 H2: 455
W: 300 H: 300
Anchors: 4x M12
Check-Flex G4-G0225
ID: 231 L: 421 H2: 483
W: 350 H: 350
Anchors: 4x M12
Check-Flex G4-G0250
ID: 254 L: 450 H2: 520
W: 350 H: 350
Anchors: 4x M12
Check-Flex G4-G0300
ID: 308 L: 605 H2: 608
W: 500 H: 500
Anchors: 4x M16
Check-Flex G4-G0400
ID: 410 L: 705 H2: 788
W: 650 H: 650
Anchors: 4x M16
Check-Flex G4-G0525
ID: 525 L: 835 H2: 958
W: 800 H: 800
Anchors: 12x M16
Check-Flex G4-G0600
ID: 616 L: 970 H2: 1096
W: 900 H: 900
Anchors: 12x M16
Check-Flex G4-G0800
ID: 812 L: 1200 H2: 1394
W: 1100 H: 1100
Anchors: 12x M20
Check-Flex G4-G0900
ID: 924 L: 1400 H2: 1690
W: 1200 H: 1200
Anchors: 20x M20
Stainless Steel Assembly
To seal to site structure
Single or Multiple valves
Table displaying model, style, pipe size range, and pipe connection options for various products.

We're your trusted experts!

We have decades of extensive experience with rubber check valve application in demanding Atlantic coastal sites. Get design, CAD drawings, specification, installation and troubleshooting advice.

Get a quote
Let's discuss your design

© 2025 Measurit Technologies Ltd

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-