Tube Trailer Recertification

TKS recertifies DOT 3A, 3AA, 3AX, 3AAX and 3T trailer1cylinders using acoustic emission in lieu of hydrostatic testing. TKS’ U.S. DOT special permit # 14584 allows for AET on DOT 3A, 3AA, 3AX, 3AAX and 3T cylinders.  Follow-up ultrasonic inspection is required only if the acoustic emission test detects an active flaw in the cylinder. Both our AE and UT inspections use the latest ASME standards as guidelines.


AE Inspection Procedure

TKS’ AE inspection procedure follows the ASTM E 1419 Standard Test for Examination of Seamless, Gas-Filled, Pressure Vessels Using Acoustic Emission and ISO 16148. Our instrumentation is calibrated on each tube tested. After calibration, the tubes are loaded to 110%. During this loading period active flaws, if present, in the cylinder’s wall will emit high frequency sound waves. These sound waves travel longitudinally in the cylinder until they are detected by the by piezoelectric sensors located at each end of the cylinder. The relative time-of-flight of the sound wave at each transducer is used to locate the flaw longitudinally.


Follow-up UT Inspection

A follow-up ultrasonic inspection is required only if the AE inspection detects an active flaw during the loading period. Our inspection procedure follows ASTM E 2223 Standard Practice for Examination of Seamless, Gas-Filled, Steel Pressure Vessels Using Angle Beam Ultrasonics.

Contact Us

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Areas We Cover

With our HQ based in State College, Pa  we cover inspections all over the USA, while also servicing international inspections , including but not limited to:







Dominican Republic

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