Definition(s)
Hydrogen Blister
Bulge in steel caused by high pressure molecular hydrogen trapped at an internal flaw within steel.
API RP 2201, Safe Hot Tapping Practices in the Petroleum & Petrochemical Industries, Fifth Edition, July 2003 (Reaffirmed October 2010), Global Standards
API RP 2009, Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries, Seventh Edition, February 2002 (Reaffirmed, March 2012), Global Standards