What is the duration of a proof test as specified by ASME B30.3?

The ASME B30.3 standard specifies that the duration of a proof test for tower cranes should be a minimum of 5 minutes. This duration is critical to ensure that the crane's structural components and operational controls can withstand the necessary operational loads without showing signs of distress or failure. A proof test is essentially a method to verify the integrity of the crane, ensuring it meets safety and operational standards before being put to use.

Conducting the proof test for 5 minutes allows sufficient time for the system to be evaluated under load, providing operators with confidence in the crane's ability to perform safely during its operational lifespan. It's essential for maintaining safety protocols in crane operations, as well as meeting regulatory requirements. A proof test shorter than this duration may not adequately demonstrate the crane's capacity to handle stress, while a longer duration may not be necessary and could lead to inefficiencies in operational scheduling.