The filter vessel is considered a pressure vessel due to its operating pressure and falls within the scope of the Pressure Equipment Directive (PED) 2014/68/EU. First the design is made in accordance to the AD-Merkblatt, then drafting and a TÜV design review follow. The casing is welded in accordance to the regulations of the AD-Merkblatt. Testing, done in the presence of the TÜV, includes X-ray, pressure tests and final inspections. Complete documentation is provided which includes operating instructions and hazard analysis.