A3A.... what does it mean? A3A.... what does it mean? pietje (Mechanical) (OP) 1 Apr 14 11:07 I have recently seen some drawings of pressure equipment which do not state a design code, but do state "category/module: A3A". Does anyone know what this means?? It is a complete mystery to me. RE: A3A.... what does it mean? XL83NL (Mechanical) 1 Apr 14 15:51 Based on your username, I assume youre dutch. First thing that comes to mind, is that A3A may mean 'article 3 para 3', which comes from PED 97/23/EC. It's also known as SEP, and you see it all the time for small vessels designed and built within/for the european market. If thats what the vessel designer/manfacturer tried to 'declare', then he's probably implying the vessel is designed acc. Sound Engineering Practice. This is no design code, but defines what requirements the PED directive spell out. These requirements are as much as the name implies... However, it may also mean something else. RE: A3A.... what does it mean? pietje (Mechanical) (OP) 1 Apr 14 16:23 That must be it... thanx!