• Thomas R. Hay, Ph.D., P.E

Recertification of Tube Trailers using Acoustic Emission Testing

Updated: Mar 11, 2020

There are many classes of DOT steel cylinders used for medical, industrial, power generation, and gas storage, such as nitrogen, oxygen, helium, hydrogen, etc. It is common to mount these cylinders on a trailer so that the desired gas may be delivered to the customer’s site and refilled at bulk gas storage facilities as required. Since these tube trailers transport certain gases, compliance with U.S. DOT Pipeline and Hazardous Material Safety regulations are required.


Part of this requirement includes a minimum 5-year re-certification process that assures the tubes or cylinders are fit for continued service. There are two competing methods for tube trailer recertification. Hydrotesting requires that the tubes be disassembled from the trailer at significant cost to the owner. Acoustic emission testing can be performed while the cylinders are mounted on the trailer at tremendous cost benefit to the owner.

Dr. Thomas R. Hay is the President at TechKnowServ. “TKS is one of the select few companies in the U.S. that has been granted Special Permits by the U.S. Department of Transportation (DOT) to retest compressed gasses cylinders with Acoustic Emission (AE) in lieu of hydrost