How does a check valve typically operate?

A check valve operates by opening and closing based on the pressure of the fluid flowing through it. It is designed to allow fluid to flow in only one direction, preventing backflow. When the pressure of the fluid exceeds the set threshold, the valve opens, allowing fluid to pass through. When the pressure drops or reverses, the valve closes to block the flow, thus ensuring that the system remains pressurized in the intended direction.

This operational principle is crucial in refrigeration systems to maintain efficiency, prevent contamination, and protect components from damage caused by reverse flow. The other options do not accurately describe how a check valve functions, as check valves do not regulate temperature, limit flow rate in a controlled manner like a flow control valve, or involve the decomposition of refrigerants.