Cast Iron Flap Valves - Rectangular

This range of flap valves has a rectangular aperture, single door and double hinges.
  • 400 to 2000mm square
  • Cast iron grade 250 (EN-GJL-250)
  • Metal to metal seals for durability and low leakage rates
  • Robust construction for durability
  • Wall or pipe mounted
  • Double door flap valves available for reduced head loss
  • Integral cast lifting lugs as standard
  • Seals resistant to erosion by grit
  • Double hung to ensure full face sealing

The primary application of flap valves is for surface water drainage associated with rivers, estuaries and sea water outfalls to prevent reverse flow conditions. Flap valves can be utilised on final effluent outfalls for sewage treatment plant to prevent flood damage within the works.

The flap valves should be positioned on the outfall structure to avoid the build-up of debris around the invert area which could prevent the valve operating correctly. Sufficient fall-away should be provided between the invert of the flap valve and the base of the outfall structure.

Flap valves are designed for all types of pipe end closures to prevent entrance of back water. These valves are supplied in various configurations to fit most installation needs. An inclined seating plane is used to ensure that the valve will operate a ‘positive close’ position.

Flap valve application on sea water outfalls should be given careful consideration due to turbulence of flow across the flap, particularly when severe wave action is involved, resulting in dislocation of the flap relative to its seals. Wherever possible the flap valve should be located in a shielded position to minimise the effects of severe wave action.

Ham Baker manufactures a comprehensive range of flap valves.  Generally, most flap valves are of single door type but double door types are also available. The cast iron series of flap valves is constructed from traditional materials utilising the most modern production techniques to provide a robust and reliable product.

Flap valves can be supplied for wall, flange or thimble mounting applications

This range of flap valves have a square/rectangular aperture, single door and double hinges. The sealing faces are secured on the frame and door with long taper countersunk pegs of the same material as the sealing faces. The flap valve is suitable for mounting on a vertical wall or thimble for seating heads up to 6 metres.

  • Fixing Bolts can be supplied on request

Note: It is recommended that at least 300mm fall away is provided at the invert to prevent fouling of the bottom of the door.