Air Filters

Some of the most important components in a PULSAIR system are the air filters. They are of particular concern if the compressed air system is old or not well maintained. Dirty, oily, moist air is the enemy of a PULSAIR pneumatic controller.

An air filter with a 40-micron filter element and an automatic drain is supplied with each PULSAIR system. The filter cleans the air supplied to the PULSAIR controller and the injection valves. To protect the air logic circuit, each PULSAIR pneumatic controller has two additional filters. The first filter has a 5-micron element. The second unit is a coalescing filter, designed to remove aerosols.

It is very important to inspect the compressed air system before starting up a new installation. Jeffrey Yap of Premier Six, our representative in Singapore, discovered how important it is to inspect the compressed air filters. Jeffrey traveled to Kuala Lumpur to assist Petronas with the startup of their new PULSAIR system. When he checked the filters he discovered that the filter bowls had filled with sand and rust.

After installation, and prior to start up, PULSAIR advises that the operator remove the filter bowl and filter element and then turn the air system on for two minutes to ensure that all installation particulate such as pipe threads, pipe thread tape, pipe weld, water, scaling, etc. be blown out of the system. The filter element and bowl can then be reassembled knowing that the vast majority of foreign materials have been removed from the line. The contractor should conduct this procedure. However, it is often forgotten in the rush to finish the installation. Instructions on the procedure to blow the lines prior to start-up are included in the Operations Manual.

While calling on a PULSAIR customer, two simple checks can be conducted to determine filter condition. Open the controller cover and then the control panel and look at the two internal filters. Turn the two screws on the right side of the control panel 90º to release the panel.

The filter elements are white when first installed. If there is any heavy discoloration, then replace the elements. If there is water present, it can be drained by turning the brass knob several turns clockwise. The knob is located at the bottom of the filter bowl. Clockwise might seem backward, but you are actually turning the fitting inside the bowl, which releases the seal so that the moisture can drain out. When the water has drained completely, turn the knob counter-clockwise to reseat the seal.

Secondly, look into the sight glass on the large Watts filter to see if water is present. If the filter is equipped with an auto drain (now standard equipment PULSAIR systems) you can press the button on the brass auto drain and purge the filter bowl. This is best done when a pail placed or held below the auto drain. If it is an older system without the auto drain, then it will have a drain knob that works like the internal filters described above.