Abstract
Task Group T-5B-6, under the direction of Group Committee T-5B for High Temperature Materials Performance, has conducted a survey by mail questionnaire devoted to the performance of tubing and fittings in Ethylene and Olefins Pyrolysis Furnaces. The purpose of the survey is to clarify the fragmentary reports about relative life of radiant tubing and fittings by collating information from a large number of ethylene production plants. Included in the survey is relative performance of seven alternative alloys, modes of deterioration, such as carburization and rupture, operational background, inspection and repair. The report is dedicated to materials, operations and process engineers associated with the petrochemical industry. Sixteen ethylene producers reported on experience in 28 plants. Tube and fitting life varies from six months to ten years depending on location in the coil, skin temperature and other variables. Carburization accelerated stress rupture, bulging, bowing, cracking and erosion are the prevalent forms of degradation.