NE197 “Maintenance Concept instead of EX Hardware Testing” is new published

The NAMUR recommendation NE197 from WG 4.1 Asset and Maintenance Management and WG 4.7 Explosion Protection has been newly published and can now be obtained from the office.

Abstract to NE 197 "Maintenance Concept instead of EX Hardware Testing"

This NAMUR recommendation provides guidance on the application of a maintenance concept that allows to carry out regular inspections of explosion-protected devices.
According to the Industrial Safety Regulation (BetrSichV), inspections for explosion protection are to be carried out with the aim of ensuring protection against hazards from explosions and fires at least until the next inspection. Some inspections can be omitted if a suitable maintenance concept is in place. This must ensure equivalently that a safe condition of the plants is maintained and explosion safety is permanently guaranteed. This NAMUR recommendation illustrates possibilities for integrating explosion protection aspects into a maintenance concept and argues why this can be accepted as equivalent to recurring inspections. The concept assumes that three fundamental conditions are met, which are:

1. Correctly assembled and installed equipment at initial commissioning.
2. Inspections from other regulations are carried out.
3. There is an established Management of Change process that also recognizes and implements changes subject to inspection.

To identify the maintenance activities to be considered, errors occurring in practice, inspection points from relevant standards, as well as indications from operating instructions were determined. These activities were evaluated with regard to possible detection methods (everyday noticeable issues, safety walkdown, testing procedures) and the required competent persons (operators, participants in safety inspections, electrical specialists).
For the organization of the maintenance concept, there are suggestions for responsibilities and accountabilities, definitions of measures and deadlines, possible implementation of maintenance/inspection/control activities.
For the proper implementation of the maintenance concept, assessment and control mechanisms are proposed.