Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

The latest general information on the Coronavirus (COVID-19) is available on For PHMSA contact information during the COVID-19 health emergency, please visit our page.

United States Department of Transportation United States Department of Transportation

Hydraulic Pressure Cycling and Performance Evaluation of Five (5) DOT-3AL 2015 Cylinders

Feb 5, 2010

This research project is a part of Failure Investigation and Metallurgical Analysis of DOT 3AL cylinders that were rejected during requalification due to internal neck-cracks. The hydraulic pressure cycling test was performed to determine the fatigue performance and fatigue failure initiation location of the DOT 3AL cylinders with internal neck-cracks. The knowledge gained from this effort will then be used to assess root-cause of the neck-cracks and consequence of using other cylinders of the same lot in transportation. This research project has been initiated and managed by DOT/Hazardous Materials Technology.

If you have any technical questions not addressed by this or associated documents, contact Mark Toughiry, 202-366-4545.

Last updated: Monday, November 27, 2017