Section III. TECHNICAL PRINCIPLES OF OPERATION

TM 5-5430-226-12

Section III. TECHNICAL PRINCIPLES OF OPERATION

Page

Principles of Operation .................................................................................................................. 1-9

Safety, Care and Handling ............................................................................................................ 1-9

1-13. PRINCIPLES OF OPERATION.

a. General. The 20K and 50K collapsible water tanks described in this manual are functional components of a

water distribution system. Any number of water tanks may be connected to the system, depending on operational

requirements.

b. Filling. Potable water to fill the water tank is supplied by a water distribution system. The system water pumps

draw water from the source (tanker truck, pipeline, or purification equipment) and pump it into the water tank through the

filler assembly. Control of water flow between the supply pumps and the water tank is accomplished by opening or

closing gate valves within the system supply circuit. As the water tank fills, the tank will enlarge. When the tank is full,

or no more water is needed, supply circuit gate valves are then closed. Excessive pressures caused by overfilling the

tank are relieved by the vent fitting assembly. The vent unseats when internal water pressure exceeds 0.10 psi (0.00680

Atmospheres). The 4-inch gate valve supplied with the tank may be installed on the filler elbow to control water tank fill

rate.

c. Discharge. When needed, water is drawn from the tank by system suction pumps, and distributed through a

network of valves and hoses to the field installed facilities. As water is drawn from the tank, tank will flatten. Water flow

between the system discharge pumps and the water tank is controlled by system gate valves. The 4-inch gate valve

supplied with the tank may be installed on the discharge elbow to control water tank discharge rate. When the tank is

empty, or no more water is needed, the down stream system discharge gate valves are then closed. Venting of the tank

during discharge is not required.

d. Draining. A hand operated valve connected to the tank drain fitting controls water flow from the tank. This valve

allows a restricted flow of water from the tank for sampling or complete drainage. When preparing the tank for

movement, the system suction pumps will draw most of the water from the tank. To ensure complete drainage, the hand

valve is opened.

1-14. SAFETY, CARE, AND HANDLING.

Observe all Warnings, Cautions and Notes in this manual. This equipment can be dangerous or may be damaged if

these instructions are not followed.

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