Ultrasonic Scanner for Heat Treatment Qualification in CNG Cylinder Fabrication

Designing and manufacturing of an automatic ultrasonic testing system (scanner) for flaw detection of compressed natural gas (CNG) cylinders, particularly in heat treatment quality assessment, is explained in this paper. Ultrasonic scanners have been installed on 5 different CNG production lines in the territory providing a fast and reliable test of cylinders with the capability of logging results according to customer demands. The paper explains both the machine specifications and the challenges faced during the manufacturing and starting up stages. A questioner was designed to collect the opinions of operators in different sites about handling easiness and performance of the scanners. It was proved that the ultrasonic scanners efficiently identify defects caused in different stages of CNG production line especially in heat treatment furnace. Besides the innovations applied to overcome the practical matters in machine manufacturing, the knowledge of ultrasonic interpreting has been transferred to operators and they earned enough proficiency to distinguish between flaws and noise signals.