Instrument air is supplied at a standard gauge pressure range of

• A. 160-185 psi
• B. 60-90 psi
• C. 100-120 psi
• D. 200-250 psi

Answer: (A)

Instrument air must be available with enough pressure to drive pneumatic devices reliably across the entire distribution network. Supplying at a higher gauge pressure provides headroom to overcome line losses, regulator drops, and variations in demand at distant outlets. By using a standard range of 160–185 psi on the gauge, the system ensures that, after regulation at the point of use, devices still receive the required operating pressure. Smaller ranges would risk insufficient pressure at the farthest points, while excessively high pressure could stress components and exceed regulator limits. Hence, 160–185 psi gauge is the appropriate standard.