137 / 648
Safety and environmental standards for fuel storage sites
Final report
135
38 Suggested data sources for SIL calculations:
Offshore reliability data handbook
■
■
2002 OREDA 2002 release 6.1;
Idaho Chemical Processing Plant, Failure Rate Database ICPP 1995;
■
■
Safety Equipment Reliability Handbook
■
■
EXIDA;
Association of chemical and associated industries in the Rhône-Alpes region
■
■
GICRA GT FMD 2002;
Database PDS data handbook
■
■
SINTEF 2006;
European Industry Reliability Data Bank
■
■
EIREDA 1995.
Annex 1 Hardware fault tolerance calculation to BS EN 61508 for sensors, final
elements and non-programmable logic solvers
YES
Redundancy
1oo1
1oo1
1oo1
1oo2 or 2oo3
HFT
0
0
0
1
SIL
1
2
3
4
Redundancy
1oo1
1oo1
1oo2 or 2oo3
1oo3 or 2oo4
HFT
0
0
1
2
SIL
1
2
3
4
Is HFT calculated to
BS EN 61508
YES
NO
NO
NO
Is Safe Fail
Fraction 90>99%
Is Safe Fail
Fraction >99%
YES
Device Type A
to
BS EN 61508
Device Type B
to
BS EN 61508
YES
Redundancy
1oo1
1oo2 or 2oo3
1oo3 or 2oo4
N/A
HFT
0
1
2
N/A
SIL
1
2
3
4
NO
Is Safe Fail
Fraction 60<90%
Device Type A
to
BS EN 61508
Device Type B
to
BS EN 61508
YES
Redundancy
1oo2 or 2oo3
1oo3 or 2oo4
N/A
N/A
HFT
1
2
N/A
N/A
SIL
1
2
3
4
Is Safe Fail
Fraction <60%
Device Type A
to
BS EN 61508
Device Type B
to
BS EN 61508
See HFT
to
BS EN 61511