Vacuum pumps are part of one of the final processes in the repair procedure. After you’ve 
diagnosed and repaired any leaks or additional issues in the system it is time to recharge. Ac Vacuum Pump Before recharging you wish to make sure the machine is free from any undesirable gasses, air, or water. If they were to stay in the machine, it would turn the essential oil it operates on into sludge and leave behind damaging impurities.
The draw on vacuum pressure pump is usually divided into its “CFM,” or Cubic Feet per Minute. To estimate what your CFM requirements, look at the tonnage of the systems you work on. Take the square root of that number and you’ll obtain the approximate CFM you must have to utilize that system. Typical residential systems need 4-5 CFM, while industrial and rooftop systems generally require as much as 6-8 CFM.