When is the operator required to visually check a delivery-hose assembly?

The operator is required to visually check a delivery-hose assembly after each unloading operation. This is a critical safety measure outlined in NFPA 58, ensuring that any potential issues such as leaks, damage, or wear can be identified and addressed promptly. Inspecting the assembly post-operation is vital as it allows the operator to detect any failures that may have occurred during the unloading process that could pose hazards such as leaks or other safety risks.

Visual inspections are essential for maintaining the integrity of the hose, as well as for the safety of personnel and the surrounding environment. Regular checks help in maintaining operational safety and compliance with safety standards, preventing accidents related to liquefied petroleum gas (LPG) handling.

The other options suggest checking at intervals that may not effectively address potential risks that could arise specifically during the unloading process. Therefore, the requirement for a visual check after each unloading operation underscores the importance of proactive safety measures in LPG operations.