Prevention of In-Service Failure of Seal Valve Axles of Blast Furnace Through Non-destructive Condition Monitoring

摘要

The upper and lower seal valves together form a key part in the top charging system of blast furnaces. The valves serve to create a gas-tight chamber during the charging of furnaces preventing the escape of blast furnace gas into the atmosphere during the operation. The axles in these valves are an integral part in the sealing mechanism of the valve flaps. Several accounts of failure of these axles in service at a Blast Furnace prompted the need for a predictive maintenance practice. This paper accounts for the failure analysis done on these axles to arrive at the root cause of failure and further the implementation of suitable NDT techniques for condition monitoring of the axles. This ultimately led to prevention of further in-service failures.