Rubber diaphragms or well known as diaphragm membrane is bladder inside pressure tank.
It is manufactured from synthetic rubber which has dark black color. This synthetic rubber diaphragm membrane is a strong and elastic object with pressure, thermal, chemical, corrosive and shear resistance.
Choosing rubber material is an important step because it directly involves with function of usages.
For example, EPDM rubber is suitable for general water such as piped water or tap water, while some butyl rubber is suitable for drinking water. There are many sizes of according to function, and the size of pressure tank.