: EN 14015 replaced the older British standard BS 2654 (which was withdrawn in 2006) and is considered an alternative to API 650 (American standard) for European and international projects.
As standard documents are copyrighted, they are typically purchased through official national standards bodies rather than downloaded for free. You can find the through these authorized retailers: En 14015 Pdf
While primarily for ambient temperatures, the standard provides guidance for elevated temperatures up to 150°C. : EN 14015 replaced the older British standard
EN 14015:2004 – Specification for the design and manufacture of site built, vertical, cylindrical, flat-bottomed, above ground, welded, steel tanks for the storage of liquids at ambient temperature and above. En 14015 Pdf