What components of a valve require the closest examination during maintenance?

The components of a valve that require the closest examination during maintenance are the seat and disc. These components are critical for the valve's functionality, as they directly control the flow of the refrigerant or other fluids through the system. The seat provides a sealing surface for the disc, which must fit precisely to prevent leaks. Any wear or damage to these elements can lead to inefficient operation, leaks, or complete valve failure.

During maintenance, checking the seat and disc can help identify signs of erosion, corrosion, or other forms of wear that could compromise the valve's performance. Ensuring that these components are in good condition is vital for maintaining system efficiency and reliability. Proper functioning of the seat and disc also ensures that the valve can fully open or close as required, which is crucial for controlling the flow within the refrigeration system. This attention to detail can prevent larger issues and costly repairs down the line, making it essential for operators to focus on these components during routine checks.