Precast Headwall with Flap Valve and Cranked Grating

We regularly supply precast headwalls with factory fitted flap valves. In this instance there was a requirement for a grating on the headwall as well. We factory fitted a cranked galvanised steel grating to the headwall. The grating had to be cranked to allow the flap valve to open fully during periods of heavy discharge through the connecting pipework.

The headwall is a Sewers for Adoption compliant unit. Along with this headwall we supplied a toe extension for the front end of the spillway to prevent the headwall slipping. Sockets are cast into the headwall for the toe extension, which must not protrude into the watercourse.