MIL-HDBK-1165
b) Damming devices for gravity flow toilets - flexible
inserts which partition the tank and prevent some of the water
from leaving the tank during a flush, resulting in less water
entering the bowl.
valve, or new reduced-flow flush valves that save water by
causing the valve to close early, reducing the amount of water
used for flushing.
d) Weighted flappers - cause the flush handle to
release early to shorten the flush duration, thereby saving
water.
e) Dual-flush devices - dual flush handles that allow
a minimal flush by moving the handle one way and a maximum flush
by moving the handle the other way.
f) Flow diverters - diverts, into the tank, a portion
of the water that would otherwise go through the overflow tube
(gravity flow).
g) Flush valve retrofits - several commercial products
exist which can increase the efficiency of the toilet flush
valves.
5.2.1.4
Replacements. New gravity flush, flush valve, and
pressurized-tank toilets are designed and manufactured to comply
with the Federal requirement of 1.6 gpf (6 lpf). Variations of
toilets, and are available from many vendors. These toilets can
be designed to look like traditional toilets.
Waterless toilets are also commercially available,
although not nearly as common as the three types above. They are
more costly to obtain and maintain, and are generally used in
areas where water is scarce. Oil, composting, or incineration
are some of the methods by which these toilets eliminate waste.
5.2.1.5
Problems and Pitfalls. As stated above, certain
retrofits may adversely affect the performance of some toilets
and may require frequent adjustment or repair. For example, take
care not to choose displacement devices that eventually will
crumble apart in the tank, such as bricks. Some retrofits are
also expensive and time consuming to install (e.g., dual-flush
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