Which components are correctly identified in the air supply unit?

The answer identifies the pressure regulation valve with an adjusting knob as a correct component of the air supply unit. This component plays a critical role in controlling the air pressure within a pneumatic system. The pressure regulation valve is designed to maintain a specific set point of pressure, allowing for adjustable settings to accommodate various operational requirements. The adjusting knob provides users with manual control to fine-tune the pressure according to the specific needs of the application. This is vital for ensuring optimal performance and preventing potential damage or inefficiencies that may arise from incorrect pressure levels.

While other components such as the oil separator, flow control valve, and air filter with a water separator are indeed essential in an air supply unit, the question specifically highlights the pressure regulation valve with an adjusting knob as the accurate identification for this context. Each of these other components has its unique function, but the emphasis here is on the importance of the pressure regulation feature, which is vital for maintaining stable system operations.