Water tank

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Water tanks are liquid storage containers, these tanks are usually storing water for human consumption. The need for water tank systems is as old as civilized man. A water tank provides for the storage of drinking water, irrigation agriculture, fire suppression, agricultural farming and livestock, chemical manufacturing, food preparation as well as many other possible solutions.

Various materials are used for making a water tank: plastics (polyethylene, polypropylene), fiberglass, concrete, stone, steel (welded or bolted, carbon or stainless). Earthen ponds function as water storage and are often referred to as tanks.

Materials used in the manufacture of these water tanks shown in picture:

Ground water tank is made of lined carbon steel, it may receive water from a water well or from surface water allowing a large volume of water to be placed in inventory and used during peak demand cycles. Elevated Water Tanks also known as water towers, by elevating the water tank the increased elevation creates a, system distribution, pressure at the tank outlet of 1 psi per 2.31 feet of elevation, thus a tank elevated to 70 feet creates about 30 psi of discharge pressure, 30 psi is sufficient for most domestic and industrial requirements. (background legs shown) Chemical contact tanks of FDA and NSF polyethylene construction, allows retention time for water and chemicals to be in contact and mix. (black tank in foreground)

Water tank application parameters include not only the type of materials to be used and the general design of the tank materials, as well as some of the following.

1. Location of the water tank (indoors, outdoors, above ground or underground)

2. Volume of water tank will need to hold

3. What the water will be used for.

4. Temperature of area where water will be stored, concern for freezing.

5. Pressure requirements

6. How is the water to be delivered into and out of the water tank.

7. Wind and Earthquake design considerations allow water tanks to survive seismic and high wind events.

Throughout history, wood, ceramic and stone have been used as water tanks. These were all naturally occurring and manmade and some tanks are still in service.

The Indus Valley Civilization (3000–1500 BC) made use of granaries and water tanks.[1] Medieval castles needed water tanks for the defenders to withstand a siege.[2] A wooden water tank found at the Año Nuevo State Reserve (California) was restored to functionality after being found completely overgrown with ivy. It had been built in 1884.[3]

Vertical cylindrical dome top tanks may hold from fifty gallons to several million gallons. Horizontal cylindrical tanks are typically used for transport; this low-profile transport storage creates a low center of gravity helping to maintain equilibrium for the transport vehicle, trailer or truck.

Hydro-pneumatic tanks are typically horizontal pressurized storage tanks. Pressurizing this reservoir of water creates a surge free delivery of stored water into the distribution system.

There are many custom configurations that include various rectangular cube shaped tanks, cone bottom and special shapes for specific design requirements.

By design a water tank/container should do no harm to the water. Water is susceptible to a number of ambient negative influences, including bacteria, viruses, algae, changes in pH, and accumulation of minerals. Correctly designed water tank systems work to mitigate these negative effects.

Articles and specifications for Water Tank applications and design considerations: American Water Works Association The AWWA is a reservoir of water tank knowledge; the association provides specifications for a variety of water storage tank applications as well as design. The AWWA's site provides scientific resources with which the reader will be able to develop an informed perspective on which to make decisions regarding their water tank requirements.

NSF International writes standards, inspects and confirms that manufactured products that come into contact with air, food, consumer goods and water are suitable for human consumption.

The Food and Drug Administration approves materials for use in storing water and food materials. Consult the Code of Federal Register for more details on water tanks.

[edit] Other uses

Architecture Dampening of highrise building movement by using a highly placed volume water tank, the volume of water creates an inertia movement opposite to the building movement, slowing the building's movement, sway.

[edit] See also

• Cistern
• Domestic water system
• Drinking water
• Electropump
• Hand pump
• Rainwater tank
• Supplier
• Water tower
• Water
• Potable water diver
• Portable water tank

[edit] External links

Wikimedia Commons has media related to: Water tanks

• American Water Works Association Produces and evolves water tank specifications. These AWWA specifications are established precedents utilized world wide by American Process Technology tank designers addressing applicable details of water tank applications and installations.
• FDA Official Regulations These specifications are both government rules and guidelines for water tank design and suggestions for water installations. This information is extracted from over 80,000 pages of the Code of Federal Register - Specifically CFR Title 21 Part 129. a US Government document.
• National Safety Foundation NSF is a non-profit organization that approves water tank products for use in applications involving interface and utilization with humanity.