The category of each item of equipment making up the assembly is based on the conditions which can occur in the assembly, taking into account:
- the volume or nominal size DN, as appropriate, of the item ;
- at least the conditions PS, TS, type or group of fluid, for which the assembly is designed, which can be lower than the intrinsic conditions of the item.
The highest category determined from these conditions will then determine the assessment of the integration of the items in the assembly.
See also PED Guidelines C-07 and C-15.
Note:
When determining the conformity assessment module(s) for an assembly, it is possible to assign to an item of pressure equipment a lower category than that to which it was originally assessed. As a consequence, an assembly which is covered by Article 4 paragraph 3 can include a CE-marked item of pressure equipment.