The Pressure Equipment Directive (PED)

The Pressure Equipment Directive (PED) harmonises national legislation of EU member states vis a vis the design, manufacture, testing and conformity assessment of pressure equipment and assemblies

Pressurised equipment contains a potential energy which has the capacity to discharge suddenly leading to catastrophic accidents and loss of life, and extensive damage to property.

However, due to new developments in industry, the use of pressure equipment is increasing in such diverse industries as hydro-carbon, fertiliser, pharmaceutical, nuclear etc.

Due to the hazardous nature of this equipment, it is imperative that strict measures be implemented to ensure that pressure equipment is manufactured to meet certain design criteria ensuring that the equipment is reasonably safe.

Until recently, most European countries had different pressure vessel design standards, eg the British Specification of Unfired Fusion Welded Pressure Vessels (BS 5500), the German Pressure Vessel Code (AD Merkblatter), and the French Code for Pressure Vessel Design (CODAP).

The different pressure vessel design codes ensured that vessels were designed and manufactured to meet certain minimum safety criteria.

However, the different codes were normally recognised, only in their country of origin.

This posed serious trade barriers if a vessel manufactured in one country was to be marketed in a country that did not fully recognise the standard to which the vessel had been manufactured.

National legislation in the country where the vessel was to be marketed often made it very difficult to market and exploit vessels that had been manufactured to a code that was different to the national code.

To overcome these technical trade barriers but at the same time taking cognisance of the hazardous nature of pressure equipment, the Pressure Equipment Directive (97/23/EC) was adopted by the European Parliament and the European Council in May 1997.The directive became fully obligatory in the European Union on May 29 2002.

The Pressure Equipment Directive (PED) harmonises national legislation of member states vis a vis the design, manufacture, testing and conformity assessment of pressure equipment and assemblies.

The Directive explicitly makes it illegal for any member state to forbid the marketing and exploitation of pressure equipment that meets all the requirements of the Directive.

There is still considerable confusion about the similarities and differences between The European Pressure Equipment Directive and The American ASME Codes.

What has to be made clear right from the start is that while the two entities might appear to be similar, they are very different by their inherent nature and purpose.

The ASME code is a set of standards that prescribes technical solutions.

The main purpose of the ASME codes is to, inter alia, provide specific technical solutions for the design, manufacture and testing of pressure equipment.

The main purpose of the Pressure Equipment Directive is to remove technical barriers among European Union Member States while at the same time ensuring that pressure equipment is designed, manufactured, and exploited in a safe manner.

As a result, the Pressure Equipment Directive is not technically prescriptive and provides a flexible regulatory environment.

If the above facts are taken into account, then there are some superficial similarities between the ASME code and the PED.

Both are 'interstate' entities.

The ASME code is valid across Federal States in the USA, while the PED is valid across European Member States in the European Union.

Both make use of a set of standards, with the PED using Harmonised European Standards while the ASME code itself comprises of a set of standards.

For instance the ASME VIII Division 1 Standard can be compared to the European EN 13445.

Both standards provide detailed technical solutions for the design of unfired pressure vessels.

Both systems make use of legally recognised bodies to assure quality during the design, manufacture and testing of pressure equipment.

The PED makes use of Notified Bodies and recognised third party organisations and the ASME code makes use of Code Inspection Agencies to undertake such work.

TUV Rheinland Group, is a notified body able to assist with all types of certification, assessment, and any issues relating to the PED.

If you have any questions, please contact us.

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