Figure 5-7.Water closet (tank type).
pressure, passing through this orifice into the upper
chamber, creates the pressure required to force the
diaphragm down and shuts off the flushing water. By
moving the flushing handle, the relief valve tilts open.
Then pressure decreases in the upper chamber to less
than that of the incoming and flushing water. The
action allows the flushing water pressure to raise the
diaphragm off the flushing seat and recycle.
Figure 5-14 shows a piston type of valve. With this
type of flush valve, the piston is drawn up when the
flushing begins, then to its closed position by the
filling of the upper chamber through the expeller
Flush valve assemblies on urinals and water
closets may be protected from unnecessary damage
and wear by installing a grip handle or guard firmly
over the handle housing. This grip handle increases the
operating life of flush valves and thereby reduces
service calls on the repair of flush valve assemblies and
Two major types of urinals in use are the floor-
mounted and wall-mounted urinals. With spacing
being limited, we will only consider some of the main
items relating to installation of the wall-hung urinal