How often must operators actuate all emergency discharge control devices designed to close the internal self-closing stop valve on a cargo tank in service?

Operators must actuate all emergency discharge control devices designed to close the internal self-closing stop valve on a cargo tank in service once a month to ensure their functionality and readiness in case of an emergency. This regular testing is crucial because it verifies that these safety mechanisms are operational and can effectively halt the flow of liquefied petroleum gas if a discharge situation arises. This frequency balances safety with practical operational measures, allowing operators to identify any issues that may prevent the emergency controls from functioning properly while minimizing the interruption of service.

Choosing a less frequent testing schedule would increase the risk of undetected malfunctions, potentially resulting in dangerous situations during an emergency. Therefore, the month-to-month requirement is aligned with safety best practices and regulatory compliance as outlined in NFPA 58.