The Pressure Equipment Directive 2014/68/EU Pressure Equipment Directive is not a standard that directly defines test methods; rather, as a framework regulation, it mandates the safety of pressure equipment and requires this safety to be technically demonstrated through harmonized standards. Therefore, test methods are determined depending on the type of equipment, its risk category, and the applicable design standard.
Within the PED framework, the fundamental testing approach is based on design verification, manufacturing quality, and final safety validation of the equipment. Calculations and strength analyses performed during the design phase are verified through inspections and tests conducted after manufacturing. In this context, non-destructive testing (NDT), mechanical testing, pressure testing, and functional testing constitute the technical backbone of PED compliance.
If the pressure equipment involves welded construction, the conformity of welds is initially verified through visual testing (VT). Subsequently, radiographic testing (RT) or ultrasonic testing (UT) is applied to assess weld continuity and detect internal defects. For the detection of surface defects, magnetic particle testing (MT) or liquid penetrant testing (PT) is carried out. These inspections are performed in accordance with relevant EN ISO NDT standards, including applicable acceptance criteria, and the results are documented within the technical file.
The final verification of pressure equipment safety is ensured through pressure testing. The most commonly applied method is the hydrostatic pressure test, in which the equipment is typically tested at 1.43 times the design pressure or at the value specified in the applicable design standard. During the test, tightness, permanent deformation, and structural integrity are evaluated. In certain cases, depending on operational requirements, pneumatic testing may also be applied; however, due to the higher risk involved, such tests are subject to stricter safety measures under PED.
Verification of material conformity is also a fundamental requirement of PED. For the materials used, material certificates in accordance with EN 10204, typically Type 3.1 or, where required, Type 3.2, must be provided. To confirm mechanical properties, tensile tests, impact tests, and, where necessary, hardness tests are performed. These tests are used to demonstrate that the material meets the assumptions defined in the design.
The main harmonized standards associated with PED can be summarized as follows:
The primary reference for pressure vessels is the EN 13445 series, which comprehensively covers design, manufacturing, inspection, and testing requirements. For piping systems, EN 13480 is used, while EN 12952 and EN 12953 series apply to water-tube and shell boilers, respectively. Welding qualifications are covered by EN ISO 15614 (WPS/PQR), welder qualifications by EN ISO 9606, and NDT personnel qualifications by EN ISO 9712. Non-destructive testing practices are defined by standards such as EN ISO 17635, EN ISO 17636, EN ISO 17638, and EN ISO 3452. For safety valves and bursting discs, the EN ISO 4126 series serves as the primary reference.