European Safety Systems Ltd.
Impress House, Mansell Road, Acton, London W3 7QH
[email protected] Tel: +44 (0)208 743 8880
Document D154-00-251-IS Issue 6 03-02-2020
Sheet 3 of 5
www.e2s.com Fax +44 (0)208 740 4200
Integrity in respect of
failure to close
SIL 2
Total Failure rate
0.133 pmh
“hazardous” failure
rate (revealed)
0 pmh
“hazardous” failure
rate (unrevealed)
0.1 pmh
“safe” failure rate
(revealed)
0.033 pmh
“safe” failure rate
(unrevealed)
0
Diagnostic Coverage
99%
System type
A
Hardware Fault
Tolerance
0
Safe Failure Fraction
>99%
PFD (hazardous
failure)
1.25 x 10
‐3
Proof Test Interval
Up to 1 year
