Tank

Tank, a vessel for storing liquids, is made of iron, cast iron, copper, ferroconcrete, and wood. Tanks usually have a cylindrical and prismatic shape. The interior of the tank must resist chemical and mechanical action of the liquid. Tanks for cold water—made of iron, cast iron, and wood lined with lead sheets—are mostly painted with iron red lead (lead and copper paints are not allowed) or, better, covered with asphalt varnish or asphalted. Tanks for hot water, iron or cast iron, are not painted; sometimes they are tinned or galvanized. Copper tanks are tinned. Wooden, ferroconcrete tanks are not painted. Tanks intended for oils cannot be painted with oil paints and varnish. Tanks for milk—iron and copper—are tinned. Tanks for drinking water must be located in special isolated rooms, well ventilated and, in cold climates, heated. The walls of the room for the tank are plastered and painted with oil paint. Wire mesh is placed in windows to prevent mosquitoes and others from entering. Tanks for hot water are made closed, with a drain pipe for steam outlet, and the walls are thermally insulated. Tanks for water that serve as emergency reservoirs and reservoirs for regulating pressure in the water supply network are called water pressure tanks and are installed in water towers. Usually tanks are equipped with supply, consumption, and overflow, or signal, pipes, and a pipe for emptying the tank during cleaning and repairs. Tanks must be periodically cleaned and washed.