scope:

This document defines the procedures and methods with which all relevant mechanical components of automated industrial valve packages that are used as final elements in a safety instrumented system can be evaluated according to the principles of EN 61508-1, −2, −4, −6 and −7 in order to integrate them into a safety instrumented system (SIS). It provides a method to determine all relevant factors, associated with the product, which should be fully taken into account and thereby meet the specific needs of users of the product.

The basic prerequisite for the application of this document is that the intended use is known. This document describes a system to avoid systematic faults to achieve the targeted Safety Integrity Level.

This document applies to automated industrial valve packages that are used as final elements in a safety instrumented system. It is applied to single components (e.g. valve, actuator or mechanical parts of solenoid valves) or to assemblies of several of these components and interconnecting parts (e.g. gears, adaptors, brackets, etc.). Electrical, electronic or programmable electronic parts have to be assessed according to EN 61508-1, −2, −4, −6 and −7.

This document does not apply to:

- manually operated valves;

- components in safety systems or risk-reducing devices that are not assessed and operated according to the principles of functional safety (e.g. automatic safety valves like pressure relief valves).

The methods described can also be used for other mechanical components in a final element of the safety instrumented system if the applicability is confirmed by appropriate expert knowledge (e.g. dampers, brakes, clutches).