The Particular Material Appraisal (PMA) procedure is one of 3 ways to approve a material for the specific requirements of the pressure equipment:
- Material which comply with harmonised standards
- Material covered by a European Approval of Material (EAM)
- Material covered by a Particular Material Appraisal (PMA)
That means, if a material has not been referenced by an EN standard or approved by the EAM procedure, a manufacturer can provide a ‘description of the solutions adopted to meet the “Essential Safety Requirements – ESR” within a PMA. This will allow the material to be used for the development of pressure equipment.
The PMA can also be used
- if a product shape or thickness is not covered by a harmonised standard
- for the specified product in exceptional cases for operating conditions outside its specified operating range.
The approval is then only valid for the specific pressure equipment, i.e. it is not a general approval.
For Pressure equipment category III and IV, a specific assessment of the PMA shall be performed by the Notified Body in charge of the conformity assessment procedure for the relevant pressure equipment. Given that the PMA relates to demonstrating that the material characteristics are suitable for the intended application, it is a crucial element for proving the safety of the equipment.
The assessment must relate to the specific application or risk assessment and take into account all necessary properties such as weldability, strength properties, corrosion resistance, temperature resistance, ageing resistance, etc.
The PED is not specific on the technical information required to develop a satisfactory PMA.
Formal requirements of PMA – Particular Material Appraisal
The PMA shall describe the material properties in a manner that is concise, complete and correct for the foreseen application. It shall comprise qualitative and quantitative data providing evidence that the relevant Essential Safety Requirements (ESR) of PED Annex I are met. (see also EN 764-4)
The responsibility for drawing up the PMA lays with the pressure equipment manufacturer. The PMA shall be part of the technical documentation in the same language. PMAs shall be available for national authorities upon request for a period of 10 years after the last pressure equipment has been manufactured.
When European harmonised material standards are available for materials similar to a material grade covered by the PMA, the material characteristics (e.g. tensile strength, yields strength, 0,2% proof strength, elongation after fracture, corrosion resistance,…) included in this European harmonised material standard are to be considered in the PMA.
