If you have never used AJVS Vacuum Pump Fluids (Vacuum Pump Oils), you probably think most Vacuum Pump Fluids (Vacuum Pump Oils) are similar and you buy based upon price.

Process engineers, maintenance technicians and plant managers at over 2,000 companies worldwide know differently.

They know from experience that a consistently superior vacuum pump fluid at a competitive price is a far better value.

They know reduced downtime, lower pump repair costs, longer fluid life and less waste disposal means a much lower overall cost and a superior value for their dollars.

Vacuum pumps depending on cfm rating can cost anywhere from $1,000.00 to $30,000 and hold anywhere from one half liter to fifteen gallons of vacuum pump oil. These fluids are generally changed three to six times per year. Does it make sense to buy the cheapest fluid or a high quality fluid engineered to perform to the pumps capabilities and to provide the ultimate protection from wear that causes pump repairs and pump failures?

With all the uncertainties in today’s business world you need a supplier you can count on.

THERMAL AND OXIDATIVE STABILITIES OF HYDROCARBON Vacuum Pump Oils

The predominant mechanism by which oils degrade or wear out in use is oxidation.  Most lubricants have a higher level of thermal stability than oxidative stability.  Thermal stability is dependent primarily on the chemical structure of the base stock.  Oxidative stability is generally obtained by the use of an additive.

Studies have shown that oils oxidize through a carbon-carbon bond to form a peroxide which in turn forms a carbonyl as a primary oxidant product. The subsequent reactions of the primary oxidation products form condensation polymers which are precursors to sludge and deposits. The primary difference among these oils are the rates of these reactions.  Vacuum Pump Oils are being subjected to ever-increasing thermal stresses.

The role of the lubricants thermal and oxidative stabilities is becoming an important factor in the  ability of vacuum pump oil to survive at higher temperatures in oxidizing environments.

THERMAL STABILITY

It is unfortunate that literature is often not explicit concerning the term thermal stability.  It is sometimes used interchangeably with thermal-oxidative stability. However, the proper definition is reserved for processes occurring in the absence of oxygen. 

MECHANISM

In the case of hydrocarbons and most other fluid classes, thermal decomposition or pyrolysis proceeds through a free-radical chain reaction process yielding many products.  Free radicals are organic fragments containing an unpaired electron, and are produced by homolysis (breaking) of the carbon-carbon bonds. These radicals can be generated by mechanical processes and thermal energy.

These radicals are highly reactive and start chain reactions by abstracting hydrogen atoms from the parent hydrocarbon.

This chain sequence will continue until the radicals are destroyed or all the reactants are consumed. Hence, a single reaction can bring about many changes in thousands of molecules.  Radicals may be destroyed by recombination or through disproportionation reactions. Radicals themselves may also fragment producing new radicals and unsaturated species. These reactions are analogous to industrial cracking.

The most general change in properties of the oil is an increase in vapor pressure of the system.  These reactions also produce higher molecular weight products which have higher boiling points.  The formation of the higher molecular weight products is important as these products are generally believed to cause viscosity increase, acidity increase, varnish and sludge formations.

AJVS offers a variety of Vacuum Pump Oils and lubricants for oil-sealed pumps and diffusion pumps that will optimize the performance of your vacuum pump. These oils have a low vapor pressure and minimal additives, which reduce the sludging that occurs with lower quality oils. Molecular distillation of premium base stocks has produced fluids that are world-wide for their quality, performance and consistent reliability. AJVS Vacuum Pump Fluids (Vacuum Pump Oils) are non-flammable, chemically inert and thermally stable. When used with proper pump filtration, AJVS PFPE fluids provide exceptionally long service life, have excellent lubricity properties and are available in viscosity grades suitable for use in all vacuum pump. AJVS oils are also used on any oil sealed rotary vane vacuum pump used for pumping pure oxygen. Diffusion Pump Fluids are designed for high vacuum and for fast pumping of large volumes of gas or vapor in production operations. AJVS offers Vacuum Pump Oils and lubricants for oil-sealed pumps and diffusion pumps, high performance greases and sealants for vacuum sealing, and mechanical and diffusion pump vacuum fluids. Molecular distillation of premium base stocks has produced fluids that are world-wide for their quality, performance and consistent reliability. Our greases and lubricants are heat stable, inert, and resists most chemicals. These greases can be used over a wide range of temperatures and meet a variety of service conditions through consistency ranges from very soft to wax-like. AJVS offers a family of high performance greases and sealants that will optimize performance, and resist degradation and thermal decomposition.

YOUR ROTARY VACUUM PUMP and OIL
The oil in vacuum pump provides many functions in the operation of this device. So proper maintenance is critical for good vacuum operation. This sheet is intended to provide you with general information, regardless of pump make and model, for proper care and feeding of your pump. Assuming that the pump is in good operating condition, mechanically, the oil level may need to be adjusted, or changed.

CAUTION : If your pump is a belt drive unit, from a separate motor, make certain the belt guard is properly mounted, for safety of the students! With the vacuum pump inlet sealed off, or closed, start up your pump, and let it operate for 15 to 20 minutes, pumping on itself. This will bring the temperature of the pump up to its normal operating level. Now check the oil level in the pump. It should be in the middle of the sight glass, or inspection port. If you cannot see the oil level, try carefully and slowly raising the end of the pump, opposite the oil level/inspection port. If the oil level is an inch or two low, it may just need some addition.
However, if the oil is dark brown in color, or worse, like black coffee, it should be replaced. The color chart below indicates the degree of thermal ageing & therefore the remaining useful life of the oil in your rotary pump.

Oil should be changed before it has reached color 4. If the oil is allowed to degrade to the extent that colors 6 & 7 are reached, the pump may have suffered damage & should be fully serviced prior to re-use. Have a suitable volume container (usually 16 to 24 ounces in volume) placed below the drain plug or valve, near the bottom of the pump.

CAUTION : The pump oil temperature by this point may be in the range of 140°F to 160°F, so protect your hands! Turn off the pump, immediately open the inlet, then open the drain plug/valve at the bottom of the bottom. The hot oil will flow horizontally for 3 or 4 inches. When the oil flow is down to just a drip every few seconds, place a rag or paper towel, directly in front of the drain, and turn on the pump for 4 to 5 seconds. This will expel any additional oil that might be in the mechanism. Remember, oil being incompressible, can squirt out the drain hole, so protect yourself. Now, close the drain port, and refill the pump, through the fill port on the top of the pump, with a fresh charge of the proper vacuum pump oil (see paragraph below), to the middle of the sight glass. Close the fill port, reseal the inlet of the pump, and restart it. You may notice that the oil level drops in the pump. Wait 5-10 minutes, then shut off the pump, open the inlet, and add enough oil at the fill port, to bring it to the middle of the sight.

VACUUM PUMP OIL
Oil used in rotary vacuum pumps is a special product, vastly different from motor oil. There are no additives such as rust inhibitors used in pump oil since such agents would be separated from the base fluid and plate out on surfaces as gummy substances.
The main function of the vacuum pump oil is to help the device perform well. It makes the engine of the device to smoothly run. Some of the vacuum pump are designed with its designated part for the oil, which can easily be removed or replace. It also have oil indicator that will help the operator if it already needs to be replaced. When it comes to changing the vacuum pump oil you must not reuse the oils that you have remove from other machine. It might cause damage to the engine of the vacuum pump, which will cause for it not to perform well. Additionally, the oil that you must use is those that are especially made for the device itself and not those from the vehicle or other type of oil.
Good vacuum pump oil is general 8 to 10 times the cost of motor oil, but is necessary for proper pump operation!