UFC 3-420-01
25 October 2004
health department, may be used for flushing water closets and urinals, and for other
approved purposes where potable water is not required. Piping containing non-potable
water, that is water not meeting accepted potable water standards, will be labeled
"NONPOTABLE WATER, DO NOT DRINK." "
C.
Add "SECTION 602.2.2 Water for landscaping. Wall faucets, wall
hydrants, lawn faucets, and yard hydrants will be located so that, with 100 feet (30 m) of
garden hose, the area can be watered without crossing the main entrance of public
buildings or barracks. The branch to the lawn faucets and yard hydrants will be
equipped with stop and waste valves. The means of watering lawn areas, flowerbeds,
and gardens will be provided as follows: (1) Wall faucets with vacuum breaker backflow
preventer on outside walls in nonfreezing climates. (2) Non-freeze wall hydrants with
vacuum breaker backflow preventer on outside walls in freezing climates. (3) Lawn
faucets with vacuum breaker backflow preventer for garden and lawn areas in
nonfreezing climates. (4) Yard non-freeze hydrants for garden and lawn areas in
freezing climates. Yard non-freeze hydrants have an automatic drain feature that can
allow ground water to enter the service line. To protect the water supply the designer
can either isolate the supply to the yard non-freeze hydrants with a double check valve
backflow preventer, or specify sanitary yard hydrants. Sanitary yard hydrants are self-
contained and do not drain to the surrounding ground, eliminating the possibility of
cross-contamination. The designer should select the most cost effective option;
sanitary yard hydrants are about three times the cost of standard non-freeze yard
hydrants.
D.
SECTION 604.1 General. Add after the last sentence: "Service lines will
enter the building in an accessible location. Large buildings will be provided with two or
more water services to ensure constant delivery to all fixtures and equipment. For
Army and Air Force projects, drain valves will be installed on the fixture side of all
service valves located inside a building. For Air Force projects, drain valves shall be
placed in locations with access to waste drains."
E.
SECTION 604.3 Water distribution system design criteria. Add after the
last sentence: "Provide piping water velocities not to exceed 10 feet per second (3.28
m/s). In hospitals and similar facilities, where a quiet system is desired, velocities are
not to exceed 7 feet per second (2.13 m/s)."
F.
SECTION 604.8 Water-pressure reducing valve or regulator. Add after
the last sentence: "For Army and Air Force projects, when the pressure of water
supply to building exceeds the required water pressure by 10 psig (69 kPa), a pressure-
reducing valve will be provided. Consideration will be given to increasing pipe sizes
based on the anticipated future installation of fixtures when performing design
calculations. For Air Force projects, building potable water pressure shall not exceed
70 psig (483 kPa)."
G.
SECTION 604.9 Water hammer. Add after the last sentence: "Only specify
commercial-type water hammer arresters, vertical capped pipe columns are not
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