Medical gas is single or mixed gases supplied centrally by medical piping systems for the treatment, diagnosis, or prevention of patients’ diseases, or for driving surgical tools and instruments, etc. In applications they also include medical vacuums and gases used for medical experiments and bacterial and embryonic cultures, etc. The most common types of medical gases are oxygen, air, vacuum, nitrous oxide, carbon dioxide, an aesthetic gases, nitrogen, etc. Medical gases are used in a variety of environments, including hospital operating rooms, emergency rooms, intensive care units, ambulances, and clinics.