Up to and including 150 mm .
The standard was significantly updated in 2019, superseding the 2009 version. It is published under various national adoptions, such as BS EN 10225-1 in the UK and DIN EN 10225-1 in Germany. en 10225-1 pdf
EN 10225-1:2019 - Weldable Steel Plates for Fixed Offshore Structures Up to and including 150 mm
It specifically subsea pipelines, risers, and process piping, which are covered by other specialized offshore standards. and process piping