I have some doubts about ASME VIII and API-650-F: Are equipments designed under these codes admitted in Germany? Must be the "AD-MERKBLATT" applied for pressure equipments?
Since 2002 every piece of mechanical pressure equipment with a design pressure above 0.5 Barg, when it is supplied or installed within the borders of the European Union, must be in compliance with European Pressure Equipment Directive 97/23/EC (PED).
As there in no harmonized design standard yet, every manufacturer is free to choice the design code for his product like ASME VIII, AD Merkblatter, Britisch Standard PS5500, Stoomwezen ,etc.
The client or end user of the product may ask for a specific code or to follow his own specification but still it has to be in compliance with the PED.