CGA C-18-2019 provides guidelines for the acoustic emission (AE) testing of certain specification tubes as authorized by special permits and equivalency certificates such as those listed in Appendix A.

Two methods of AE testing are addressed: method A and method B. Method A, which is approved in the United States by DOT and in Canada by TC, consists of an AE test performed during pneumatic pressurization to at least 110% of the normal fill pressure or marked service pressure, whichever is greater. This requalification test replaces the water jacket hydrostatic test. Method B, which is approved in Canada, consists of an AE test performed during the hydrostatic proof pressurization to the requalification pressure of the tube.

NOTE-Both methods A and B require additional ultrasonic verification of AE indications depending on the operational criteria defined in the applicable special permit or equivalency certificate.