PRESSURISED EQUIPMENTDIRECTIVE 97/23/EC
Background
The Pressurised Equipment Directive 97/23/EC, the PED, applies to pressure equipment and assemblies with a maximum allowable pressure greater than 0.5 ( 7.25 psi) bar above atmospheric pressure.
The principle used is to take greater and greater precautions, the greater the energy in the system. In addition, the hazard presented by the fluid itself is taken into account.
Pressure Equipment. Pressure equipment` means vessels, piping, safety accessories and pressure accessories.
'Piping` means piping components intended for the transport of fluids, when connected together for integration into a pressure system.
'Assemblies` means several pieces of pressure equipment assembled by a manufacturer to constitute an integrated and functional whole.
Exclusions
Among the many exclusions listed in the PED are:
- Pipelines used for the conveyance of fluids or substances
- Water distribution systems
- Equipment coming under the simple pressure vessel directive 87/404/EEC
- Aerosols
- Motor Vehicles as defined in the applicable directives
- Well control equipment
- Casings or machinery where the design is dictated by the static and dynamic operational effects and for which pressure is not a significant design factor.
- Flexible casings, e.g. tyres, air cushions, balls used for play, inflatable craft
It is important to take advice on exclusions if there is any doubt.
In addition, if the equipment category is not higher than one, the following are also excluded if:
- Machinery for which Council Directive 98/37/EC applies
- Lifts for which Council Directive and Council Directive 95/16/EC applies
- LVD equipment for which Council Directive 73/23/EEC applies
- Medical devices for which Council Directive 93/42/EEC applies
- Gas Appliances for which Council Directive 90/396/EEC applies
- ATEX equipment for which Council Directive 94/9/EC applies
In these cases compliance with the particular directives are deemed to be sufficient. However it is always the responsibility of the manufacturer to ensure that equipment supplied can be operated safely and it is advisable to take into account the Essential Requirements of the PED in conducting any safety or risk assessment.
Warning ! Manufacturers have a duty of care to ensure that no unacceptable hazards exist regardless of these exclusions.
Essential Requirements
The Essential Requirements listed in Annex I to the directive apply to all equipments included in the PED.
Groups of Fluid
- Group 1 - dangerous fluids are defined as:
- explosive, or
- extremely flammable, or highly flammable, or flammable or
- very toxic, or toxic, or
- oxidizing.
- Group 2 comprises all other fluids
Categories of Equipment
The category of equipment depends on the energy contained within the equipment ( pressure *volume) and the nature of the fluid it contains. Gases are treated differently to liquids and dangerous fluids are considered separately from other fluids. The category is determined by reference to the appropriate graph in Annex II of the Directive.
The lowest “category” is Safe Engineering Practice or SEP, then Category I to Category IV. The higher the category the greater the potential to cause harm and the more demanding the compliance criteria are. A notified Body should be involved for any pressure equipment with a category higher than II.
Conformance Assessment. For more information contact info@atlanticbridge.co.uk