Condensation pump includes a compared strictly requirements to oil quality, for the reason that property of vacuum diffusion pump oil has a great effect on pumping gas performance of diffusion pump. Consequently, principle requirements to condensation pump oil as follows: the first requirement would be the molecular amount of pump oil really should be big, such is usually to reduced limit pressure of pump; the 2nd requirement is pump oil in under room temperature have saturated steam pressure to low. That is to makes pump work underneath the high export pressure. Along with other requirements are pump oil in boiling temperature have saturated steam pressure should the size of possible the new stability of pump oil (not easily decomposition under high temperature) and antioxidant properties (the pump performance won't be changed because oxidation when contact atmospheric) are better; melting point and frigidity viscosity have to be low; as well as other requirements are nontoxic, corrosion resistance, low cost, etc. What are link between pumping on limit pressure? The type and composition of pump oil includes a great effect on the ultimate pressure on the pump. If you use the next oil diffusion pump from the same structure diffusion pumps, THE ultimate pressure reach to 10-5 kPa; if switch the signal from use No. 275 silicone oil, the greatest pressure could reach to 10-7 Pa, ultimate pressure might be lower to two orders of magnitude. Vacuum systems pumped gas partial pressure also varies with pump oil, this can be a impact that pumping oil brings. For instance, oil diffusion pumps air extraction system without special measures are challenging to obtain cleaner vacuum. Vapor pressure of Saturated pump oil is to obtain high vacuum and need pump oil at room temperature has lower vapour pressure. As well as the pumps are needed to work under ruthless at the same time, and want pump oil inside the boiler temperature has higher vapour pressure. Therefore, the most suitable diffusion pump oil its saturation vapor pressure with temperature changes in the slope of the curve. To avoid accidents in the vacuum unit debugging should observe the following issues:(1) the best call time vacuum unit and master vacuum unit operating rules;(2) the proper use of vacuum gauges and master its rules;(3)repairs, cleaning vacuum unit and screw within the moving parts is prohibited when it is running; (4)check if the water, oil, lubrication is normal prior to the pump is started;(5) the moving parts needs to have protective measures in the event that they fly out;(6) the workshop must be built with fire extinguishers, sand boxes along with other fire-extinguishing appliances.