Vacuum pumps: Be air aware

While all manufacturing plants should aim for the highest possible air quality, this is particularly important for sites operating in the food and beverage, pharmaceutical and electronics industries; essentially any plant requiring a particularly ‘sterile’ environment. Given the nature of the goods being produced, which are potentially ingested, air purity around manufacturing processes is essential.

There are stringent standards in place that regulate the quality and specification of compressed air applications. ISO8573 is the group of international standards stipulating the quality of compressed air. Made up of nine separate parts, part one highlights the amount of contamination allowed in each cubic metre of compressed air and the remaining eight specify the methods of testing for a range of contaminants. This ranges from oil aerosol content and humidity, to solid particle and oil vapour content.

Surprisingly, however, there is no regulation in place for exhaust air quality from vacuum pumps. Most sites will follow the recognised principles of the Hazard Analysis Critical Control Point (HACCP) to ensure they are complying with hygiene legislation, eliminating any potential hazards or reducing these to an acceptable level. Yet, while manufacturing processes are scrutinised in great detail, ancillary processes and utilities can often be omitted. Crucially, this can mean potential risks from equipment such as vacuum pumps are overlooked.

With vacuum systems generally located around the production environment, a contaminated pump exhaust can be hazardous.

An oily issue

The majority of vacuum pumps currently in use are oil-lubricated and many applications will operate without any problems arising. Nevertheless, there is the potential risk of oil discharging from the exhaust of this type of pump, which presents a particularly significant issue for sites where air quality cannot be compromised.

In addition to oil discharge from the exhaust, operating at high temperatures and an open-ended inlet port could result in oil carrying over from the pump, while a separator element may fail due to misuse or through the use of non-genuine spare parts.

The potential risk of leaks from an oil-lubricated vacuum pump can be avoided through a range of measures. These include using a food grade lubricant, fitting a downstream exhaust filter or remotely piping the exhaust air. For those concerned about the risks of oil-lubricated vacuum pumps, Gardner Denver can help identify and reduce any risks through a free site survey, which may extend to working with the production team to ensure the equipment is included in the HACCP assessment.

Achieving the greatest air quality

Yet for sensitive manufacturing environments, it may make sense to implement an oil-free model. Oil-free vacuum pumps have been developed specifically to meet the needs of manufacturers that require only the highest air purity environments. In short, these do not require the same level of maintenance as oil-lubricated models, as there is clearly no need to replace the oil or filters, which contribute to higher operating costs over a pump’s lifetime.

Another clear advantage to an oil-free vacuum pump is that it does not have to be removed to carry out essential maintenance servicing, resulting in no equipment downtime or associated costs, from oil, waste oil disposal or labour.

Gardner Denver offers a range of oil-free vacuum pumps, each suited to the particular requirements of individual applications. For instance, the S-VSI dry-running vacuum pump for packaging under protective gas needs no coolant or sealing medium in the suction chamber. This particular pump is water-cooled and offers low heat emission into the environment.

With potentially increased outputs and greater uptime, the benefits of an oil-free model are clear. It is important that industrial plants are aware of the issues around vacuum pump air quality, and the opportunities to reduce the likelihood of any issues arising.