Maintaining Compressed Air, Gas & Steam Filters and Replacing Filter Cartridge Elements

Compressed air is one of the most expensive utilities to employ. It’s common to overlook its true cost in many plant operations. Properly maintain your compressed air system to control costs and keep them from rising during operation. Improper filter maintenance reduces compressed air output due to the pressure loss that dirty or spent cartridges cause. In short, depleted elements exhibit high differential pressures. Differential pressure is the pressure loss between unfiltered compressed air and the pressure after filtration. In addition to controlling costs, proper maintenance reduces the oil and dirt in your compressed air lines. These contaminants could also be in contact with your final product!

Element Life of Particulate Filters

The application, run cycles, and filter operating environment affect the lifespan of the element cartridges. Use differential pressure gauges to monitor and determine coalescing, pre and activated carbon filters’ end of life. When the differential pressure rises too high, it shows that the effective life of the element cartridge has reached its end. High differential pressure at the filter indicates a saturated or blocked cartridge(s) that reduces the output air pressure.

Differential pressure gauges indicate when your filter cartridge element is blocked. They also help isolate and determine if the cartridge is the cause of pressure drops in your system. In general, the pressure drop from the compressor to the point of use should not exceed 10 percent. Your continued use of a saturated filter element leads to lower output pressure, as well as increased cost of operation.

Replacing Elements for Sterile Filters

Sterile filter elements operate differently than standard coalescing filters and have unique expectations with respect to their filtration characteristics. Whereas the coalescing filters and pre-filters remove particulates, oil, and water, sterile filter elements remove only bacterial contaminants. Properly configured, your complete sterile system setup should have a dryer to provide a moisture-free atmosphere in which the sterile element operates.

To effectively maintain your sterile compressed air system, you must sterilize the filters during any system shutdown, as well as on regularly scheduled intervals. You should replace or sterilize the sterile filter elements on a monthly basis. A qualified microbiologist should regularly check the sterile filters for proper operation.

Steam Filter Maintenance

Steam filters and their elements operate as particulate filters. Generally, they remove particulate matter, such as rust and scale that is common in steam systems. Depending on your application requirements, steam filter cartridges have effective pore size ranging from .2 to 100 microns in size. Because they are composed of sintered stainless steel, bronze, brass or titanium, they are cleanable and have a much longer service life than other particulate filters, such as pre-filters and coalescing filters. As a rule of thumb, we recommended that you replace your steam filter elements after a maximum of six cleanings to maintain proper flow and acceptable differential pressure. It’s necessary that you replace the elements because particulate matter can be permanently lodged in the pores of the element.

Compressed air, gas, and steam filters are critical to protect the various components of an industrial system. They ensure clean downstream output at point-of-use for equipment, tools, and delicate instruments. Additionally, they help maintain system efficiency and restrain operational costs. To keep your system operating at peak efficiency, you must replace your spent filter cartridge elements either on a scheduled basis (like sterile filters) or when differential pressures are too high (as with pre-filters and coalescing filters).