As water pressure changes, the volume of air in a bladder. pressure tank contracts and expands. Periodically, the amount. of air in the tank should be measured and the tank recharged if. the air is too low. Bladder pressure tanks do not provide any. useful water storage capacity.
Add Image. Exotic Materials are the strange and unusual elements produced by science, nature, or some strange alien force. Such materials could be alloys, isotopes, chemicals, and such.
DEFINITION of 'Raw Materials'. A material or substance used in the primary production or manufacturing of a good. Raw materials are often natural resources such as oil, iron and wood.Before being used in the manufacturing process raw materials often are altered to be used in different processes.Raw materials are often referred to as commodities, which are bought and sold on commodities exchanges around the world.Next Up.aw materials are often natural resources such as oil, iron and wood. Before being used in the manufacturing process raw materials often are altered to be used in different processes. Raw materials are often referred to as commodities, which are bought and sold on commodities exchanges around the world. Next Up.