CAGI Compressed Air Specialist Practice Exam

When determining the percent increase in consumed brake horsepower (BHP) for every 2 psig increase in plant pressure, it's essential to understand the relationship between pressure and horsepower in compressed air systems. Generally, as the pressure in a compressed air system increases, the power required to compress that air also increases.

For many compressor systems, a rule of thumb is that the BHP required increases by approximately 1% for every 2 psig increase in pressure. This concept stems from the fact that the power required to do work on the air increases with pressure due to the thermodynamic principles governing the behavior of gases. Therefore, when the pressure is raised, more energy is necessary to maintain that increased pressure, leading to an increase in the horsepower consumed.

Thus, the correct answer reflects this common industry standard, where a 2 psig increase results in about a 1 percent increase in the brake horsepower consumed by the system. This understanding is crucial for plant operators and engineers when assessing the efficiency and performance of compressed air systems, allowing them to make informed decisions about pressure settings and energy consumption.