PED 97/23/EC (Pressure Equipment Directive) adopted by the European Parliament and the European Council on May 29, 1997 was published on May 29, 2002. Previously, manufacturers of pressure equipment could decide if the product would meet the Pressure Equipment Directive requirements or continue applying the existing national legislation. On May 29, 2002, the PED was made obligatory throughout the European Economic Area.
The main aim of the Pressure Equipment Directive is to harmonize the European national legislations with regards to the design, manufacture, testing and conformity assessment of pressure equipment and assemblies with a maximum allowable pressure greater than 0.5 bar gauge. Pressure equipment can be represented by piping, vessels, safety accessories and pressure accessories. Assemblies means several pieces of pressure equipment assembled to form an integrated whole.
The directive arises from the “New Approach to Technical Harmonization and Standards” allowing for a flexible regulatory environment, without technical barriers to trade.
The scope of the Pressure Equipment Directive is rather wide, covering equipment such as:
- Reaction vessels
- Pressurised storage containers
- Heat exchangers
- Steam generators
- Shell and water tube boilers
- Industrial pipe work
- Safety devices and pressure accessories
Such pressure equipment is widely used in the process industries (chemical, petrochemical, biochemical, food processing), high temperature process industry, refrigeration and energy generation. Furthermore, the directive covers equipment normally used in any general engineering process (such as gas cylinders and certain compressed air equipment).
Typical examples of safety devices include:
- Safety valves
- Buckling rods
- Controlled safety pressure relief systems
- Pressure switches
- Temperature switches and fluid level switches
According to the directive, pressure equipment and assemblies above specified pressure and/or volume thresholds must:
- be safe
- meet essential safety requirements covering design, manufacture and testing
- satisfy appropriate conformity assessment procedures
- carry the CE mark and other information
Additional to the performance requirements, manufacturers are obliged to provide explicit instructions with equipment they sell, complete a specified declaration of conformity, as well as maintain a technical file of information about how the equipment was designed and manufactured.
To ensure that products put on the European market meet the requirements of the PED, it is essential to establish the PED classification. Pressure equipment classification is based on the hazard presented by its application. Hazard is determined by the stored energy and the nature of the contained fluid. A manufacturer is obliged to classify the pressure equipment into one of four conformity assessment categories: Categories I to IV.
Assessment and conformity measures differ according to a category, starting from self-certification for the lowest hazard -category I, ending with the full quality management and notified body testing for category IV equipment.
Upon completion of the conformity assessment and if the equipment or assembly complies with the provision of the Pressure Equipment Directive, the manufacturer is required to affix the CE-marking to each item of pressure equipment or assembly and draw up a Declaration of Conformity.
For non-EU manufacturers: Appoint a European Authorized Representative established within the European Community.
The directive portrays European Law in forced within the European Economic Area (EEA); non-compliance with the directive’s requirements will result in the removal of the product from the market and the revoking of the CE marking affixed on the equipment.