One major problem that emerges in compressed air systems is pressure drop, which is marked by a loss of pressure between the compressor and the end point. While a certain amount of pressure drop is inevitable, it should never amount to more than a 10 percent loss of pressure during a given application. Otherwise, higher pressure demands end up being placed on the compressor, which results in more rapid wear and tear across the entirety of an air system.

For each pound of pressure either increased or decreased, a power plus or minus 0.5 percent is required. For example, a five percent power savings can be gained with a decrease of 10 psig. On a 100 hp compressor, this would translate to $1,740 in annual energy savings.

Pressure drop is usually caused by trouble with the pipes and weaknesses at the filters and dryers. Unfortunately, system operators will often compensate for the pressure loss by boosting the system pressure, which results in costlier operations. The correct way to handle this issue is to check for problems at the filters and dryers and replace certain items as necessary.

It’s crucial for air system pipes to remain clean and free of dirt, rust or other contaminants. After all, compressed air reaches its end point through these pipes. When contaminants are present, air pressure weakens, and the problem gradually accelerates when left un–rectified. The pipes should always remove air from the top of the air line, otherwise contaminants will travel to the pneumatic tools.

Airstream contamination increases with velocity, which in turn increases with restrictions in pipe size. Basically, the velocity of the pipes that run to the end point should be 50 seconds or less, while the interconnecting pipes and main headers should have velocity in the range of 20 to 30 feet per second. System velocity can be calculated by dividing the flow in cfm by the pipe’s compression ratio, divided by the pipe area, divided by 60.

Another factor that can impact condensation is the ambient temperature that surrounds a facility. Simply put, condensation levels multiply as temperatures rise from average to humid. For example, a 200 hp compressor will produce roughly 50 gallons of condensate over the course of a 60–degree day. However, that same machine will generate more than five times the amount of condensate if the temperature is 30 degrees higher. A 200 hp compressor will produce roughly 50 gallons of condensate over the course of a 60-degree day.

Further inefficiency can stem from problems with the system drains, which are designed to deal with condensation. Drains are placed at strategic points along a dental air compressor system, such as the tank, dryer and aftercooler. The trouble emerges when the drain fails to do its job properly, and sludge accumulates along the drainage points from a mix of water, oil and dirt.

Some of the most common mistakes in compressed air maintenance are easily avoidable if everyone on an air system staff understands how to properly care for the equipment at hand. From the compressor itself to the various parts that make up an air system, routine inspections along key areas must be made for signs of wear, condensation and dirt deposits.