What is Visual Cylinder Inspection(aka "tank inspection")? 
Become a PSI-PCI Trained Visual Cylinder Inspector! XS Scuba-New Hydro Rules
From XS Scuba:
The Department of Transportation has recently changed Special Permit 14157.
SP14157 covers all Worthington Cylinder X-Series, 3442 PSI steel scuba cylinders. Changes to SP14157 include how the cylinder is evaluated for pass / fail at the time of requalification hydro test. These cylinders are no longer evaluated by the percentage of Permanent Expansion. These cylinders are now evaluated for pass / fail by the REE (Rejection Elastic Expansion). That is, the Elastic Expansion cannot exceed the Rejection Elastic Expansion. The REE is stamped into the shoulder of every X-Series Worthington cylinder and it is located on our website.
A similar change has also occurred to Transport Canada's TC-SU 4957 Equivalency Certificate.
Please note that these changes do not have any effect on Worthington LP-Series DOT 3AA steel cylinders or Worthington aluminum 3AL aluminum cylinders.
Worthington Cylinders continues to recommend that the Hydrostatic Requalification Procedures released on June 4, 2010 are followed.
Please click here to go to XS Scuba website to review more information regarding the release, download the DOT or TC notice and get the REE for testing
