What occurs between two connected points in a pneumatic system when a pressure differential exists?

• A. Heat
• B. Flow
• C. Torque
• D. Viscosity

Answer: (B)

When there’s a pressure difference between two connected points in a pneumatic system, the higher-pressure region pushes air toward the lower-pressure region. This movement is the flow of air, driven by the pressure gradient and resisted by the system’s components (pipes, valves, fittings). The flow continues to move air until pressures balance or the system reaches its operating state. Heat can be produced by compression or friction, but the immediate phenomenon caused by the pressure difference is the flow. Torque isn’t involved in this straight-line movement of air, and viscosity describes how easily the air can flow rather than what is happening; it influences the rate of flow but is not the process itself.