The definition of assemblies in Article 2(6) does not prohibit non PED pressure equipment (pressurised equipment excluded by Article 1 paragraph 2 to be included in an assembly covered by the PED.
In the case of a PED assembly, the global conformity assessment required by Article 14 paragraph 6 does not include the assessment of non-PED items of pressure equipment.
The assessment of
- the integration of the assembly
- the protection of the assembly against exceeding the permissible operating limits
shall be conducted in the light by the highest category of PED items of pressure equipment included, but it shall also take account of the characteristics of the non-PED equipment.
See also PED Guideline C-12.
Note 1:
A hydraulic system of an item of machinery can meet the definition of Article 2(6), but as it is not intended to be put into service as such, it is not covered by Article 4 paragraph 2(b) (see PED Guideline C-10). On the other hand, a refrigeration system is considered to be a PED assembly even if some of the pieces under pressure are excluded from PED.
Note 2:
In the sense of PED, an assembly is a pressurised system; a machine-tool, an earthmoving machinery, an agricultural tractor, a mobile crane is not, as a whole, a PED assembly.