Find out how simple preventative maintenance can keep your presses running at peak levels and head off costly downtime and quality issues.
By Rick Fuqua
A coalescing filter is used to physically extract water vapor from the incoming air when the air is regulated
at the press. This is accomplished by forcing the air to pass through a filter similar to what is used in fish tanks to make air bubbles. In our application, it is designed to rake the water droplets from the air. This system works for smaller quantities of moisture, but your refrigerated dryer does the bulk of the moisture extraction upstream by cooling the air and forcing the moisture to condense and fall out of the air before entering the FRL at the machine.
The water trapped or physically extracted from the coalescing filter is expected to collect in a clear plastic bowl until either the machine operator pushes a button to drain it out or a internal float is pushed up by the accumulating water (similar to a toilet float) and the water is pushed out. The float then resets itself and air no longer passes out of the bottom. The filter will leak air continuously when a contaminant prevents the floats from reseating themselves. You’ll likely have to cut the air supply and drain any air trapped in the lines before removing the filter. Once the filter is removed, you may only have to tap on the bowl to dislodge the dirt or particle that may be in the way of the float reseating itself.
The oiler follows the filter and regulator (Figure 1). The oiler is designed to add a drop of lightweight oil into the air so that the inside of pneumatic parts, such as valves and air cylinders, move freely. This oil addition can be a problem when too much oil is let in. It is always better to have too little than too much. Manufacturers suggest a drop after so many indexes. This is a bit of a guess and should be checked occasionally or metered up or down based on the setting’s effects on your press. The most important and often missed maintenance step is filling the bowl with the right type of oil when it runs out.
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