Comosion resistance and light weight have made composite materials the best choice for many high pressure gas applications. However, progress has been hampered by the limitations of tradhional NDT
inspection methods and lack of understanding about ftilure mechanisms, One solution which has emerged is the use of Acoustic Emission to monitor the composite pressure vessel during periodic proof tests. The
emission generated can be used to determine the existence of hidden mechanical defects and corrosion which may have signiikantly lowered the burst strength. A data base of over 4000 NGV (natural gas vehicle)
containers will be used to exemplify the usefulness of the method.
Keywords: Acoustic Emission composite cylinders, test method, nondestructive testing stress wave emissions.