Compressed air: Find the leaks, lower the pressure, and measure the results
By Mark Krisa, Ingersoll Rand
No savings will be realized until the volume of air required to support leaks is reduced and a measureable reduction in compressor supply power achieved.
The leak-hunting activity is usually allocated to a member of the maintenance staff. This task is usually treated as an event driven by a corporate energy leader as part of a cost reduction goal. Even though an ultrasonic leak detector is reasonably easy to use, there is still a learning curve that can only be traversed through experience. Consequently, the time allotted to locating leaks by a technician using the tool for the first time or annually delivers marginal results.
Without a target or measureable goal, any number of identified leaks can be considered sufficient. The most significant issue associated with achieving savings can be attributed to core competency and responsibility. Maintenance teams are responsible for production equipment and subsystems required to support operations.
Because production and process goals are defined, measured, and monitored, delivering operation goals is the priority and repairing identified leaks falls to the bottom of the priority list. Without a measurable validation process, the majority of identified leaks typically remain unrepaired.
As a global organization, Ingersoll Rand has developed standard work process and tools to support a formal leak assessment program. When executing our leak assessments, it is common to find a significant volume of leaks that internal resources never identified, in addition to other leaks with old tags still in place.
In addition to identifying leaks, it is important to quantify and prioritize all leaks based on volume. A prioritized list of leaks can be used to develop leak repair objectives. A “better practice” will include a third-party validation process to measure targeted leaks and confirm they are repaired.
Lower the pressure
The second most frequently addressed “good practice” is lowering compressed air system pressure. For positive displacement compressors, like rotary screw and reciprocating compressors, reducing pressure at the discharge of the compressor will reduce the input power. It is important to note that the actual reduction in compressor power can vary depending on design and current operating pressure.