What are the typical indicators of a pneumatic circuit fault?

• A. No movement, slow movement, jerking, irregular speed, audible leaks, valve sticking or mis-sequencing
• B. Only No movement
• C. Rapid, smooth operation
• D. No audible leaks

Answer: (A)

When a pneumatic circuit has a fault, you’ll typically see a range of signs rather than just one. The indicators listed—no movement, slow movement, jerking, irregular speed, audible leaks, and valve sticking or mis-sequencing—cover the spectrum of common problems: leaks causing pressure loss and slow or unstable motion, sticking valves causing abrupt or delayed moves, and incorrect sequencing leading to mis-timed actions. This breadth makes them the best telltale set for faults.

If you only note no movement, you miss other frequent faults like slow or jerky motion or mis-sequencing. A system that moves rapidly and smoothly is usually not a fault; and silent or non-audible leaks can still hide problems, so relying on audible leaks alone isn’t reliable. That’s why the comprehensive list of symptoms is the most accurate indicator of typical pneumatic circuit faults.