YOKOGAWA RAMC User Manual

<A2. SAFETY INSTRUMENTED SYSTEMS INSTALLATION>
A2-5
IM 01R01B02-00E-E 12th edition October 01, 2014 -00
All Rights Reserved. Copyright © 2003, Rota Yokogawa
A2.4 Assessment results
A2.4.1 Safety related parameters
The following results have been obtained from the assessment report Report No.: ROTA YOKOGAWA 05/04-
20 R001 Version V4, Revision R1; August 2010 issued by exida.
Average PFD values have been calculated assuming a Diagnostic Coverage (DC) of 99%, a mission time of
10 years and a Mean Time To Restoration of 24 hours.
Table A2.2: Summary for RAMC ([V1]) with fail-safe limit switches
3
– Failure rates

Prole 2 Prole 4
Fail Safe Detected (λSD) 0 FIT 0 FIT
Fail Safe Undetected (λSU) 143 FIT 197 FIT
Fail Dangerous Detected (λDD) 0 FIT 0 FIT
Fail Dangerous Undetected (λDU) 55 FIT 94 FIT
SFF
4
72.4% 67.8%
MTBF 528 years 349 years
SIL AC
5
SIL2 SIL2
Safety metrics according to ISO 13849-1
6
:
MTTF
d
(years) 2076 1214
DC 0% 0%
Category (CAT) CAT 1 CAT 1
Performance Level (required) PL
r
= c PL
r
= c
Performance Level (calculated) 5.50E-08 1/h 9.40E-08 1/h
T[Proof] = 1 year T[Proof] = 5 years T[Proof] = 10 years
PFDAVG = 2.63E-04 PFDAVG = 1.22E-03 PFDAVG = 2.41E-03
Table A2.3: Summary for RAMC ([V1]) with standard limit switches
7
– Failure rates

Prole 2 Prole 4
Fail Safe Detected (λSD) 0 FIT 0 FIT
Fail Safe Undetected (λSU) 174 FIT 228 FIT
Fail Dangerous Detected (λDD) 0 FIT 0 FIT
Fail Dangerous Undetected (λDU) 94 FIT 133 FIT
SFF
4
65.0% 63.2%
MTBF 400 years 288 years
SIL AC
5
SIL2 SIL2
Safety metrics according to ISO 13849-1
6
:
MTTF
d
(years) 1214 858
DC 0% 0%
Category (CAT) CAT 1 CAT 1
Performance Level (required) PL
r
= c PL
r
= c
Performance Level (calculated) 9.40E-08 1/h 1.33E-07 1/h
T[Proof] = 1 year T[Proof] = 5 years T[Proof] = 10 years
PFDAVG = 4.49E-04 PFDAVG = 2.08E-03 PFDAVG = 4.12E-03

YOKOGAWA RAMC Specifications

General

Brand	YOKOGAWA
Model	RAMC
Category	Measuring Instruments
Language	English