Ultrasonic Inspection for Neck/Shoulder Cracks in Aluminum Gas Cylinders

Recent catastrophic failures of Self Contained Underwater Breathing Apparatus (SCUBA) aluminum gas cylinders and similar air tanks have generated the need for a highly reliable, low cost inspection method to insure the integrity of these tanks. The failures of these tanks have been the result of crack formation in the neck and shoulder area. The cracks originate from the interior wall and can result in tank rupture. At least one such failure has resulted in serious injury. The proposed program will develop an ultrasonic based inspection system that will locate the cracks before they can cause the tanks to fail. The inspection system that will be developed will be able to discriminate between benign and critical cracks, indicating when the tanks need to be removed from service. The technique will be rapid, highly reliable, simple to implement, and will require little operator training. The expected goal is to make the inspection system sufficiently inexpensive to be deployed at every refill station and rapid enough to perform a complete inspection during a refill procedure. Such an inspection system will insure that no aluminum air tank in use will contain dangerous cracks located in the neck and shoulder area.