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Explosion protection and SIL brought together by Standards

Explosions often cause major damage. Therefore, it’s not surprising that large sums of money are invested in safety precautions in order to prevent explosions. In this case functional performance and reliability of such equipment is essential.

The new standard NEN-EN 50495 brings Explosion protection and Functional safety (in terms of Safety Integrity Levels, SIL) together. Not only for safety precautions (as described in the NEN-EN-IEC 60079) but also for the functional precautions that need to be assessed.

 

Safety meassures versus ignition sources

New in this context is the European standard EN 50495. In addition to the regulations of the 60079 - and 61241-series, this standard provides regulations for electrical security meassures, in order to reduce the risk of electrical equipment being a source of ignition in hazardous areas.

An example is the direct temperature monitoring of the monitored component (such as a PTC thermistor in an electric motor). But also facilities to monitor processes to avoid overheating (for example level control to avoid that a submersible pump runs dry or protection for overcharging a battery.

Functional safety and reliability

The safety of such devices depend on the functional performance and the reliability. The NEN-EN 50495 offers a method to investigate, determine and test this reliability. 
This standard is the connection between the regulations from the 60079- and 61241-series for explosion protection and the Functunal Safety (SIL) as described in the NEN-EN-IEC 61508 and the NEN-EN-IEC 61511.

Harmonized standard

By applying the NEN-EN 50495 the requirements of the European ATEX directive, ATEX 95, are essentially fulfilled. As are the requirements related to the Dutch legislation.

Source: NEN.nl

More information: http://www.nen.nl/web/Actueel/Norm-brengt-explosieveiligheid-en-SIL-bij-elkaar.htm