Failure Modes and Estimated Failure Rates
Section 5:
Failure Modes and Estimated
Failure Rates
Table 1�
Failure Rates – EL-O-Matic E-Serie Pneumatic Actuator
Failure Category
Failure Rate (in FIT)
Spring-Return
Double-Acting
Fail Safe
76
0
Fail Dangerous Undetected
342
362
No Effect
1550
1285
Table 2�
Failure Rates – EL-O-Matic P-Serie Pneumatic Actuator
Failure Category
Failure Rate (in FIT)
Spring-Return
Double-Acting
Fail Safe
80
0
Fail Dangerous Undetected
559
465
No Effect
1993
1265
The failure rates for the EL-O-Matic E and P Series pneumatic actuator when performing
partial valve stroke testing are listed in the table below:
Table 3�
Failure Rates – EL-O-Matic E-Serie Pneumatic Actuator with partial valve stroke testing
Failure Category
Failure Rate (in FIT)
Spring-Return
Double-Acting
Fail Safe
76
0
Fail Dangerous Detected
225
201
Fail Dangerous Undetected
117
161
No Effect
1550
1285
Table 4�
Failure Rates – EL-O-Matic P-Serie Pneumatic Actuator with partial valve stroke testing
Failure Category
Failure Rate (in FIT)
Spring-Return
Double-Acting
Fail Safe
80
0
Fail Dangerous Detected
370
256
Fail Dangerous Undetected
189
209
No Effect
1993
1265
NOTICE
No internal diagnostics is included in the device. These values are valid when taken in
account the maintenance interval and procedure described in Section 7, and for the
expected lifetime defined in Section 4.
SIL Safety Manual
DOC.SILM.EEP.EN Rev. 0
April 2017
6
Section 5: Failure Modes and Estimated Failure Rates