Volume 8 – Mechanical and Electrical Services - Malaysia Geoportal

Chapter 2 GATE DESIGN
Figure 2.17 Cast Iron Sluice Gate
2.2.4 Flap Gate
These are automatic gates that allow for flow in one direction but prevent water from flowing back
through the gate. They open automatically under a back-head and close automatically under a facehead.
Flap gates could be round or rectangular shape and normally of cast iron, aluminium, HDPE
or fibreglass material. Flap gates consist of a cover or flap that is hinged to the body through hinge
arms to open on pivot points. For good water tightness, bronze seats machined to a fine finish are
furnished onto both the body and cover or rubber seats are incorporated in a groove on the body of
the flap gate. Flap gates could be of the round type design suitable for wall or pipe mounted as
shown in Figure 2.18 with the typical materials for HDPE Flap Gate. It could also be of the
rectangular type suitable for wall mounted as shown in Figure 2.19 with material specification for
each component.
March 2009 2-15