The Pressure Equipment Directive (97/23/EC) was adopted by the European Parliament and the European Council in May 1997. It has initially come into force on 29 November 1999. From that date until 29 May 2002 manufacturers had a choice between applying the pressure equipment directive or continuing with the application of the existing national legislation. From 30 May 2002 the pressure equipment directive is obligatory throughout the EU.

　　The directive provides, together with the directives related to simple pressure vessels (2009/105/EC), transportable pressure equipment (99/36/EC) and Aerosol Dispensers (75/324/EEC), for an adequate legislative framework on European level for equipment subject to a pressure hazard.

　　The PED Directive arises from the European Community's Programme for the elimination of technical barriers to trade and is formulated under the "New Approach to Technical Harmonisation and Standards". Its purpose is to harmonise national laws of Member States regarding the design, manufacture, testing and conformity assessment of pressure equipment and assemblies of pressure equipment. It therefore aims to ensure the free placing on the market and putting into service of the equipment within the European Union and the European Economic Area. Formulated under the New Approach the directive provides for a flexible regulatory environment that does not impose any detailed technical solution. This approach allows European industry to develop new techniques thereby increasing international competitiveness. The pressure equipment directive is one of a series of technical harmonisation directives for machinery, electrical equipment, medical devices, simple pressure vessels, gas appliances etc.

　　The Directive concerns items such as vessels, pressurised storage containers, heat exchangers, steam generators, boilers, industrial piping, safety devices and pressure accessories. Such pressure equipment is widely used in the process industries (oil & gas, chemical, pharmaceutical, plastics and rubber and the food and beverage industry), high temperature process industry (glass, paper and board), energy production and in the supply of utilities, heating, air conditioning and gas storage and transportation.

　　Under the Community regime of the Directive, pressure equipment and assemblies above specified pressure and/or volume thresholds must:

　　l be safe;

　　l meet essential safety requirements covering design, manufacture and testing;

　　l satisfy appropriate conformity assessment procedures; and

　　l carry the CE marking and other information.

　　Pressure equipment and assemblies below the specified pressure / volume thresholds must:

　　l be safe;

　　l be designed and manufactured in accordance with the sound engineering practice of a Member State; and

　　l bear specified markings (but not the CE marking).