Flanges and their joints - Design rules for gasketed circular flange connections - Part 4: Qualification of personnel competency in the assembly of bolted joints fitted to equipment subject to the Pressure Equipment Directive; German version CEN/TS 1591-4:2007
Sustainability criteria for the production of biofuels and bioliquids for energy applications - Principles, criteria, indicators and verifiers - Part 1: Terminology (includes Amendment A1:2019)