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3.4 Function
3.4.4 Oil Functions
3.4.5 Pump Lubrication
To ensure efficient operation and proper maintenance, and to minimize noise and oil vapours, it is important
to use the correct type and quantity of oil. Directorr™ Premium vacuum oil has been especially developed
to have the proper viscosity, low vapour pressure, and chemical stability needed to produce peak pumping
efficiency. The ultimate vacuum guarantee on Welch pumps applies only when this oil is used. Each pump
is supplied with sufficient oil for filling. Additional oil is available. See chapter 8 Overview of Accessories.
3.4.6 Exhaust Filter
Any oil-sealed vacuum pump tends to discharge oil mist from its exhaust port when the pump operates
under high-flow conditions, such as when the pump’s intake is at or near atmospheric pressure. Typically,
oil mist in the form of a white puff of “smoke” can be seen from the exhaust port when no filter is used.
Once the vacuum level and the corresponding air flow through the pump are reduced, very little, if any,
oil mist will be emitted.
An exhaust filter is recommended for any vacuum pump installation where the pump operates at high
intake pressures for a prolonged period of time. Oil droplets entrained in the pump’s exhaust are removed
by the exhaust filter element. Use of an exhaust filter typically reduces or baffles pump noise as well.
Exhaust filters are sometimes referred to as oil mist eliminators. See chapter 8 Overview of Accessories.
Vacuum pump is shipped without oil inside to prevent possible spillage during shipment.
Oil must be added prior to use!
WARNING !
The oil fulfils the following functions in the vacuum pump:
•
Lubricating the sliding parts, such as rotor, vane, radial shaft seals
•
Sealing the moving parts against the stator wall to reduce leaks
•
Conducting the heat of compression to the metal walls (cooling)
The oil transports the polluted particles and corrosive media and thus effects continuous cleaning of
the internal surfaces.
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DESCRIPTION
