Medical vacuum is provided by means of a vacuum central plant. The vacuum system should always be used in conjunction with vacuum control units that include vacuum jars. In fact, it is not a gas, it is a negative pressure used for suctioning patients and for anesthetic gas scavenging system. Typically, vacuum is delivered at pressure of 400 mmHg (53 KPa) below atmospheric pressure.
Vacuum pumps are mechanised devices that create a negative pressure in the piping system. The pumps should alternate automatically. A reservoir tank is used for storage to permit cycling on and off instead of continuous operation. Each pump should be capable of maintaining 75 per cent of calculated demand during peak time.