Help or Hindrance for Compliance with the PED

The new standard EN16668 Industrial valves — Requirements and testing for metallic valves as pressure accessories has been published.

By Martin Greenhalgh

It has been developed to help manufacturers by specifying ways to meet the essential safety requirements of Annex 1 of the Pressure Equipment Directive 2014/68/EU. It has an extensive Annex ZA addressing all the Essential Safety Requirements. It is intended that it will become a harmonised standard. However following publication it has been realised that there are procedural errors in the text which prevent it from being accepted as a harmonised standard. An amendment is urgently being prepared to correct these errors. It does not address requirements and testing of Safety Accessories so Safety Valves and Bursting discs are excluded from the Scope.

Whatever the final outcome of the UK’s negotiations to leave the EU in terms of UK legislation, those BVAA members supplying into EU countries will still have to CE mark their products and the products will have to comply with Essential Safety Requirements of Annex 1. EN16668 has therefore to be seriously considered as to whether it is a help or a hindrance to manufactures preparing their Declarations of Conformity. It is strongly recommended that all members obtain a copy and consider its contents carefully.

In considering whether this document is helpful or a hindrance we should look back into the history of harmonised standard development. In the 1990’s we were developing the harmonised standards to support the PED 97/23/EC. At that time it was proposed to develop a single document addressing all the essential safety requirements but that proposal was rejected by the CEN consultant to the PED. So TC69 adopted the approach of preparing various basic standards, which had Annex ZA’s addressing specific parts of the Essential Safety Requirements for example EN12516 and EN19. Also the product standards made reference to these basic standards so the product standards were allowed to have Annex ZA’s which addressed specific parts of the Essential Safety Requirements.

This approach has led to a lack of consistency between the Annex ZA’s in the product standards and to potential gaps in addressing all the Essential Safety Requirements by the Basic Standards.

CEN TC69 recognised these issues and EN16668 has been prepared to try and provide consistency in addressing all the Essential Safety requirements.

If we were back in 1997 we would all welcome this document. Today we have all addressed the issues of satisfying the Essential Safety Requirements. We all have our Declarations of Conformity. So what help is the new standard? It may be helpful in simplifying our existing Declarations of Conformity. It may help us with addressing some of the Essential Requirements that we had not thought too hard about.

At the moment EN16668 is not referenced in EN product standards so it is not mandatory to follow its requirements. BS EN 16767 Industrial valves — Steel and cast iron check valves does not refer to it but the proposed revision to EN593 does. The Butterfly Valve TEG review of prEN 593 has shown conflicts between the text of prEN593 and EN16668. These conflicts are not acceptable and need to be removed. There is also the more fundamental concern that Butterfly valve manufacturers and no doubt in later years other product manufacturers will be forced to adopt EN16668 as their route to addressing the Essential Safety Requirements if they wish to claim compliance to the standard for their product.

EN 16668 addresses the issue of welding of castings. It includes definitions from EN ISO 11970. Finishing welding is defined as welding of the casting. Repair welding is defined as welding to repair a casting that has been in service. According to EN16668 finishing welding is only allowed on steel castings.

It is early days yet in the life of EN16668. We need to closely monitor any revisions to product standards that propose referring to EN16668. We need feedback from members on whether they are using EN16668 and the difficulties or not in doing so. The Valve WG will provide the forum for our monitoring of this standard.

Published in Valve User Magazine Issue 38

Autumn 2018 // Issue 46
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