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.
This article needs development. To help develop this article, click 'Edit this article' above. The term â deleterious materials â is a broad one, encompassing not only materials that are dangerous to health or which are the causes of failures in buildings, but increasingly, materials which are environmentally damaging.he list of deleterious materials has always remained fluid because as technology advances new products come onto the market and medical research establishes new risks to health. Clauses in contracts and appointment documents often refer to compliance with 'Good Practice in the selection of construction materials'.