MIL-HDBK-1165
a) Locate and repair leaks in hoses, spray rinse
fixtures, etc.
b)
Wash only full loads in residential rack-type
dishwashers.
c) Use minimum flow rates suggested by the
manufacturer.
d) For conveyor types, reduce flow rates for the pre-
wash spray, if present, to minimum acceptable levels.
e) For conveyor types, ensure that the flow of water
stops when no dishes are present.
5.2.7.3
Retrofits. The following retrofits can save water with
existing dishwashers:
a) Install pressure or flow regulators to limit flow
to the manufacturer's suggested levels.
b) Equip conveyer types with an "electric eye" to
automatically shut off the water unless dishes are present.
c) For conveyor types, limit or eliminate scrapping
troughs (used to carry away food waste in a stream of water to
the garbage disposal).
5.2.7.4
Replacements. New rack-type dishwashers include one or
more features to aid in conserving water. One feature is an
improved spray arm geometry, developed in Europe, which allows
water to be sprayed alternately through the top and bottom spray
arms, instead of both at once. Less water is used while the wash
quality remains the same. Other features include an improved
sump fill control that makes use of timers to control the volume
of water initially admitted to the dishwasher, and an improved
sump geometry that protects the pump (from drawing in air) with a
smaller volume of water. Additionally, improved filters and more
efficient motors permit enhanced cleaning power with less water.
Newer commercial warewashers also make use of the
booster heater. Moreover, since large amounts of water are used
in the pre-rinse phase of commercial dishwashing, manufacturers
are developing methods and equipment to reduce the amount of
water used for this stage. One method is called ultrasonic pre-
rinse. As the name implies, the rack of dishes is immersed in a
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