Vacuum Pump Oil Properties – What you must know Vacuum Pump oil is manufactured by just about 6 or 7 manufacturers in the entire world; each claiming that its products are the best. Adding to the confusion, equipment manufacturers having tie-ups with Vacuum pump oil manufacturers ‘recommend’ a specific Vacuum pump oil only. This ‘recommended’ oil is invariably very costly and cuts into the already thin margins of Vacuum users. Question is – Is there really no alternative to the expensive ‘recommended’ vacuum pump oil? Is there a way in which the pump user can know – transparently and with confidence – exactly what he is buying? We have been approached by many high vacuum users asking us to elaborate on important properties of Vacuum pump oil so that they can use an appropriate oil that does not punch a hole in their pocket and at the same time works perfectly for their costly equipment. A good Vacuum Pump Oil should have the following properties: (1) Vapor Pressure – Regardless of its other qualities, a vacuum pump oil is of no use if its vapor pressure is so high that it contaminates the working region of the vacuum chamber. A minimum vapor pressure is necessary. A vacuum pump oil with a really low vapor pressure will (a) improve performance (b) simplify trapping and (c) reduce contamination. The best vacuum pump oil will have a vapor pressure less than 0.1 Pa (l0-3 Torr) at its operating pressure. Lower the Vapor Pressure Better the Vacuum pump oil.
(2) Lubricating Ability – Two types of vacuum pump oil provide lubrication. They are – Rotary Vacuum Pump Oil and Roots Blower vacuum pump oil. This ability of the oil prevents inner wear and tear of the pump and increases the pump life. So a very important property of Vacuum Pump Oil is lubricating ability. Synthetic oils typically have 11% more lubricating ability compared to mineral Vacuum oils.