What is a backwater valve?
A backwater valve is an accessory which, when installed at the
point where back flowing could eventually occur, remains open under
normal circumstances to allow the free evacuation of drainages,
but closes automatically when there is an accidental return of the
flow of sewage systems or drainage canals.
There are four models of backwater valves to protect the places,
which are exposed to suffering accidental back flowing. These models
It allows maintaining the alignment that initially has the
pipe where it should be installed, it can work in horizontal
position or to be inclined to adapt to the design slope.
It is a previous model's variant that is offered with a manifold
top to allow inspecting its interior, to connect an ejector
pump to discharge sewage excess through the valve and to inject
pressured waters for works of inner cleaning, as can see in
its installation diagram.
It is used in drainage pipes or in the dikes that protect
ditches, when their diameters overcome 250 millimeters (10
inches). They should be installed inside a pit or at the outlet
of the dike.
Especially appropriate valve for situations in those that
the bottom part of the outlet pipe of the pit, is to considerable
depth with relationship to the pipes that there discharge,
it is installed at the bottom of the box and there it joins
all the discharges through its cover.
Drainage gates are valves which are fabricated with fiberglass,
to prevent the reverse flow of the sewer system. They have
a pendular hatch which opens whenever the exit pressure is
greater than the possible backwater pressure thereby allowing
the exit flow but not backwater into the protected location.
Given that proper functioning of the values require a significant
volume of water to open the hatch, it is recommended that
the pipes that need protection have a minimum diameter of
300 milimeters (12 inches). Such diameter transports the necessary