China 'GB/T 20490-2006
' standard english version:
NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA
GB/T 20490-2006
Seamless and welded (except submerged arc-welded) steel tubes for pressure purposes - Ultrasonic testing for the detection of laminar imperfections 承压无缝和焊接(埋弧焊除外)钢管分层的超声检测
Issued Date:2006-09-12
Implemented Date:2007-02-01
Issued by:
The Standardization Administration of the People's Republic of China