TM 10-4610-240-10
TM 08580C-10/1
T.O. 40W4-13-21
12-20. COLD WEATHER.
WARNING
Do not operate heater in fuel vapor areas or areas lacking adequate ventilation. Inhalation of fumes
will result in serious illness or death.
Locating, installing and operating the equipment at subfreezing temperatures requires taking precautions. Adequate
shelter and heating are required when operating in temperatures below 320F (0 ). When locating the equipment, take
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advantage of existing shelter and windbreaks. Erect tenting shelters for protection. The filtered water storage tanks may
be installed inside a tent or other shelter. Filtered water may be recirculated with the distribution pump between the two
filtered water storage tanks to prevent freezing in the hose lines, tank outlets and pump. Fuel, coal or wood burning
heaters or other heating devices may be installed inside the erected tents to protect the equipment and prevent freezing
of water. When the equipment is to be shut down, all hoses must be disconnected from pumps, and all pumps, hoses,
pipes and tanks drained quickly. All drain and vent valves must be opened and all equipment inspected to assure
complete drainage. Leave covers on pumps. During cold weather, keep in mind the following warnings, cautions and
procedures:
CAUTION
Turn valves slowly during cold weather, because metal contracts and becomes very brittle.
a. Inspect the ROWPU closely for split or frozen hoses, clogged strainer, etc.
WARNING
To prevent hands from freezing to metal, wear rubber gloves when handling and setting valves.
CAUTION
If raw water hoses freeze, poor water flow will reduce pressure in R.O. pump. The R.O. PUMP LOW
PRESSURE lamp will come on and R.O. pump will shut itself off. Bring hoses under cover until ice
melts.
NOTE
The ROWPU produces less product water when the temperature of raw water drops.
b. When the ROWPU is shut down during cold weather (temperature falls below 32 (0 ), remove the R.O.
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elements (paragraph 3-4), and cartridge filters (paragraph 3-5). Store the elements indoors or in a tent where the
temperature is above freezing and allow them to dry. Drain all water from ROWPU as follows:
WARNING
Make sure drained water runs toward lower ground (downstream) as far from the raw water source as
possible.
(1) Drain ROWPU pipe, filters, and connections:
(a) Open seven drain valves (paragraph 2-7a).
(b) Open five vent valves (paragraph 2-7b).
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