Sil Capability; General Requirements - Emerson Fisher 1052 Safety Manual

Instruction Manual Supplement
D103790X012

SIL Capability

Systematic Integrity
Figure 2. exida SIL 3 Capable
The product has met manufacturer design process requirements of SIL 3. These are intended to achieve sufficient
integrity against systematic errors of design by the manufacturer. A SIF designed with this product must not be used at
a SIL level higher than stated without "prior use" justification by the end user or diverse technology redundancy in the
design.
Random Integrity
The Fisher 1052 diaphragm rotary actuator is classified as Type A devices according to IEC 61508, having a hardware
fault tolerance of 0. The complete final element subsystem, with a 1052 actuator and rotary valve as the final control
element, will need to be evaluated to determine the Safe Failure Fraction of the subsystem. If the SFF for the entire
final element subsystem is between 60% and 90%, a design can meet SIL 2 @ HFT=0.
Safety Parameters
For detailed failure rate information refer to the Failure Modes, Effects and Diagnostic Analysis Report for the Fisher
1052 actuator.
Connection of the Fisher 1052 Actuator to the SIS Logic-solver
The final element subsystem (consisting of a positioner, 1052 actuator, and a rotary valve) is connected to the safety
rated logic solver which is actively performing the Safety Function as well as any automatic diagnostics designed to
diagnose potentially dangerous failures within the 1052 actuator, valve and any other final element components (i.e.
Partial Valve Stroke Test).

General Requirements

The system's response time shall be less than process safety time. The final control element subsystem needs to be
sized properly to assure that the response time is less than the required process safety time. The 1052 actuator will
move the valve to its safe state in less than the required SIF's safety time under the specified conditions.
All SIS components including the 1052 actuator must be operational before process start­up.
The user shall verify that the 1052 actuator is suitable for use in safety applications.
Personnel performing maintenance and testing on the 1052 actuator and valve shall be competent to do so.
Results from the proof tests shall be recorded and reviewed periodically.
1052 Actuator
October 2017
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