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.
Indirect Materials. In accounting, indirect material is a category of indirect cost. Indirect materials are materials that are used in a production process, but are not directly traceable to a cost object. Indirect material costs are considered overhead costs and treated accordingly.