Why is it recommended to blast the burner after changing fuel tanks?

It is important to blast the burner after changing fuel tanks to ensure the new tank is functioning properly. This process allows the pilot to verify that the fuel is flowing correctly and that the burner ignites and operates as expected with the new fuel source. By igniting the burner, any potential issues with the fuel delivery system can be identified immediately, ensuring that the balloon or airship is ready for safe operation.

Testing for leaks is certainly critical, but it typically involves other methods such as visual inspections or using soapy water around the fuel connections rather than simply blasting the burner. Cooling down the burner or draining old fuel does not address the primary concern of confirming the functionality of the new fuel tank right after it has been installed. Thus, the main focus of blasting the burner is to validate the performance of the new system before taking off.