What is the air pressure on the air side of a hydraulic accumulator charged with a preload of 1,000 PSI when the hydraulic system pressure is at 3,000 PSI?

The correct answer considers the operating principles of hydraulic accumulators. In a hydraulic accumulator, the air side is typically preloaded with a certain air pressure, which in this case is 1,000 PSI.

When the hydraulic system operates at a pressure of 3,000 PSI, the pressure in the hydraulic fluid side communicates with the air side of the accumulator. The pressure in the air side will equal the sum of the preload air pressure and the pressure exerted by the hydraulic system. Since the hydraulic system provides a pressure of 3,000 PSI and the accumulator was preloaded with 1,000 PSI, the air side’s pressure essentially balances with the hydraulic system's pressure during operation, resulting in it reflecting the same level as the hydraulic side.

Therefore, the air pressure on the air side of the hydraulic accumulator equals the hydraulic system pressure of 3,000 PSI, which is why this is the correct answer. The operation of the accumulator is designed to handle fluctuations in hydraulic pressure while maintaining the calculated air cushion effectively.