Although petroleum oil filling is a subset of the automotive products industry, there many distinct producers of motor oil with packaging operations that only fill motor oil and none of the other automotive products such as cleaners, additives, etc. These dedicated filling lines produce high volumes of oil products e.g. 10w40 motor oil or chain saw motor oil and are optimized for this kind of production.
Filling machines for the oil and lube business are the same as those used to fill liquid soaps. Depending on the range of viscosities of the producer’s product line, a piston filling machines is generally used. A product line that includes heavy greases would definitely use a piston filler. A product line that only fills lighter motor oils can be filled in a piston filler, an an overflow filling machine, or a servo pump machine. Because these products are sold volumetrically, the overflow filling machine is used infrequently as the container might possibly give away product due to expansion of the container under pressure. Although the piston filler is a more common machine in this industry, the servo pump filling machine has found increasing favor because petroleum based oils volumes vary significantly with ambient filling temperature and piston fillers require more adjustments in this regard.

Overflow filling machines are generally used by smaller producers with specialty petroleum products where the output volume is not so critical and where a high degree of flexibility is needed. Companies who produce both light motor oils and lubricants as well as fuel and engine additives with very low viscosities are likely to find these machines very attractive because they are easy to setup, require few to no changeparts and can fill a wide range of container sizes. One major advantage is that should the temperature of these products change, the fill level in the container remains the same. This is a fundamental feature of the overflow filling machine that is very useful in some applications. A disadvantage of this machine (although probably not to these smaller producers), is the viscosity limitation. As the viscosity increases, the output decreases and at some viscosity level, the filling machine will not work at all. In this case, a positive displacement type of filling machine is needed e.g. a piston filling machine or a servo pump filling machine.

If the petroleum products producer is filling heavy greases, piston filling machines are the machine of choice. Thick products like this will simply will not pass through an overflow filling machine and some very heavy greases will cause pumps in a servo filling machine to cavitate. This type of filling machine will also effectively produce lighter motor oils and additives and very high speeds per nozzle. In fact, many heavy greases are heated to become more flowable in a piston filler thereby substantially increasing the machines daily output. Although more costly than an overflow filling machine, the piston filler has an excellent cost to performance profile. These filling machines are also very accurate which is important for producing commodity based products. The disadvantage of a piston filling machine is that changeovers are slow and if product bulk density changes, all pistons need to be recalibrated to fill the same volume. This can be a tedious process and can reduce daily output during periods of substantial ambient temperature changes. But is should also be noted that larger producers of petroleum oil products generally control the process delivery temperature carefully as well as control the temperature in the filling machine fluid path and hopper. This being the case, the piston filler is excellent for filling motor oils.

The Servo Pump Filling Machine uses a computer controlled pump dedicated to each filling nozzle. This allows for total programmatic control of all filling parameters with unlimited fill sizes, high volumetric accuracy and the ability to deliver a very wide range of viscosities in to almost any container. Because many of these petroleum products bulk densities change with temperature, it is difficult for the producer to monitor and adjust for different container volumes in a conventional piston filling machine. Because the servo pump filling machine is computer controlled, recipes for instantaneous changeovers for different filling environments can be programmed into the machine. This type of filling machine can also be self adjusting to ambient temperature by linking a thermal product probe to the operating system. These machine are also high output machines at nearly the same output per head of a piston filling machine. However, the utility of this filling machine comes at a high capital cost per nozzle. Each servo controlled pump/nozzle combination typically costs over $10,000 each. In some businesses, the flexibility and performance of this type of filling machine has large operational benefits. A petroleum products producer that has many different products with varying densities but the same fill sizes will find the servo pump filler to be a real time saver during changeovers.