New T/O Program

Introducing a New Certification Mark

The National Board T/O Program for
Pressure Relief Valve Certified Testing Organizations


The new T/O program formalizes the “Test Only” process by providing National Board certification to organizations conducting inservice testing of pressure relief valves. The program includes adjustment for restoring nameplate set pressure and provides customer and inspector confidence in testing capabilities.

T/O Certificates of Authorization will be extended to current VR certificate holders. New applicants can obtain a T/O Certificate of Authorization by meeting program requirements.

For more information, click here or refer to the following articles in the summer 2016 issue of the BULLETIN: Inservice Testing for Pressure Relief Valves on page 6, and T/O Program for National Board-Certified Testing Organizations – A New Mark of Quality, on page 8.