Vacuum Pump Filters and Oil Separators

Common Problems Caused By Old Vacuum Pump Filters and Separators

As pumps get older, performance levels drop away. This can be due to pump body wear, wear of mechanical parts like bearings and vanes, or consumable items like seals.

Neglected filters have become blocked and inefficient.

Filtration and separation is an area that can easily be overlooked and your pumps can be compromised through low-quality filtration, or filters and oil separators not being changed when needed.

Pumps can usually be found in low areas of the factory which are susceptible to being in a less clean environment. Also pumps work at high temperatures, which causes more stress on their working parts.

On oil lubricated pumps the oil internally lubricating the pump can be burnt away. This causes the oil to lose its viscosity and become thick, if not resolved this can eventually lead to pump failure. The oil vapour or mist caused by burnt oil is exhausted through the unit. It is the job of the oil separators (also known as oil mist eliminators – OME) to filter the oil particles (droplets/mist) from any exhaust the pump is depositing into the atmosphere.

With an oil lubricated vacuum pump, it is essential that regular maintenance takes place. This will help prolong the life of the pumps. When separators become saturated the oil mist will be exhausted into the factory and the pump will lose performance. Saturated separators will also lead to a poor working environment in the factory.

The situation with dry-running vacuum pumps is similar. It is essential to clean and maintain both internal and external filters to keep the pump cool and allow for the free flow of air.

If filters are blocked, a cycle of issues can combine to make each one worse. For instance, when pumps work hot, excessive heat can lead to pump failures, and blocked vacuum pump filters can cause restricted pump performance and excessive heat.

How vacuum pump filters and oil separators Work

There are several types of vacuum pump filters and oil separators in use depending on the pump type. Each manufacturer like Becker, Busch, Elmo Rietschle, Gardner Denver and DVP has their own oil separators and filters.

Oil Lubricated pumps can have several different types of filters. Oil Separators or oil mist eliminators. These are made from nylon or polyester media and filter oil mist or vapour internally in the unit before any air is exhausted to the atmosphere. Some oil separators have non-return valves internally to reduce noise and help pumping efficiencies.

Oil Lubricated Pumps

Oil Filters are a metal filter screwed externally onto the sump of pumps. These filter out burnt oil or solids from the oil in the sump. Metal Mesh Filters are also found in the sump of oil-lubricated pumps, again filtering sump oil before it is circulated around the pump.

Dry Running Pumps

Paper Filters can be found internally usually on dry-running rotary vane pumps or claw units. These act as pre-filters so filter any inlet air to stop contaminants from entering the pump. On the exhaust of dry running carbon vane pumps, there is a carbon dust separator designed to filter any carbon dust from the air before it is exhausted.

External Filters – These are in-line filters that filter air before arrival at the inlet of the pump. These can be made of paper, nylon or polyester. These can be found in canister-type filters and have BSP port sizes so can be installed in-line onto pipework, with spring clips on the canister lid to allow for easy access to the filter element. Generally, paper filters are used for dry air only.

OEM Filters – Sometimes original equipment manufacturers can design vacuum pump filters and oil separators for their machinery which they feel are necessary. For example, Heidelberg printing machines often have large cabinet filters to filter contaminants like spray powder before it enters the units. These cabinet filters are available through our sister company Printers Superstore.