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. are materials that are not an integral (physical) part of the finished good, or represent a minor part of the finished good to be economically traced to the finished good or have a very small physical association with the finished product. Examples of indirect materials are glue, screws, and other small items.