What was found
IAH - FLIGHT 2434, THE CREW REPORTED THAT THE PACK 2 VALVE CLOSED IN FLIGHT, AND WERE UNABLE TO RESET. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT AND RE-SECURED THE PACK 2 DISTRIBUTION MUFFLER, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.