Vacuum Pumps

1. Determine the condition of the vacuum pump oil. Take a small sample from the pump drain in a clean container to see if there is any contamination such as metal particles or water.

2. Maintain a proper level of oil in the reservoir. If there is too much oil the vacuum pump has no place to exhaust the vapors. If too little oil in the reservoir there is no oil for sealing.

3. Before starting any vacuum pump the pump should be preheated to at least 140^°F to 160^°F. That means the pump should be started at least 30 minutes before the pump is opened to the system. If the pump is opened to the system while the pump and oil are cold, any contamination will stay in the pump and oil and not be exhausted.

4. A good practice is to verify the blank-off pressure of the pump before it is needed. The blank-off pressure is the pressure with the pump isolated from the system. To do this a vacuum sensor will have to be installed on the pump.

• The blank-off pressure should be at least 50 millitorr below the lowest required operating pressure.

• Every permanently mounted pump should have an exhaust piping drop leg that can be drained. Any contamination exhausting from the pump will collect in the drop leg rather than recontaminating the oil.

5. Any visible oil around the vacuum pump is a sign that oil is leaking out. Such a leak to atmosphere could be stealing efficiency.