Cone Bottom Tanks
Some plastic tanks have a cone bottom, meaning it is angled to come to a point. They are used when complete drainage of the materials or liquids inside is necessary. Usually white in color, these tanks are made out of polypropylene or polyethylene, depending on what they are holding. Cone bottom tanks can hold 15 to 13,000 gallons and are used for water storage, wine fermentation, biodiesel and fuel holding. FDA approved tanks are used for food and medical applications. Because the bottom comes to a point, cone bottom tanks require some sort of stand in order to stay upright. They function both indoors and outside, are measured in gallons and have different degrees of slope, the standard of which is 90º, although 30º, 45º and 60º are available.
Like all plastic tanks, cone bottom tanks come in different grades. Industrial tanks are heavy walled and used for handling the toughest acids and caustics. Commercial grade are designed for less aggressive materials and chemicals, and are often used for food processing. Economy are lighter in weight. The tank stands vary according to the size and weight of the cone bottom tank. Larger tanks rest on carbon steel or stainless steel piping stands, while lighter and smaller tanks use fiberglass or plastic stands. Most standard sized tanks have about an 18 inch clearance between the bottom of the tip and the floor. Cone bottom tanks also have different types of tops, including closed dome, closed flat top, open top with a 90º angle and flanged rim.