SIL Claims for Equipment. Use of SIL X in the description of a component or subsystem is to indicate in 'short form' its capability for use in a SIL X application.

Note: Appropriate measures for these items would have been adopted to avoid systematic faults. The manufacturer or supplier will provides the required documentation and figures to support the use of the device, i.e. SFF for specified conditions, PFD for defined test intervals, failure modes, hardware fault tolerance and measures for avoiding systematic faults. These may be supported by third party assessment. However, the complete loop has to be analysed before the SIL of the SIF can be determined.