November 2017
SIL Safety Manual
SM-025-GVO Rev. 0
6
Section 3: Functional Specification
Functional Specification
Section 3:
Functional Specification
The safety function performed by Emerson actuator series GVO-CLP-SR/FS is defined as
follows:
The actuator performs the safety function on demand if it delivers a full stroke driven by
the spring, moving the valve to the safe position (either closed or open depending upon
the valve to be actuated) when the system is de-energized.
The choice of the safety function to be implemented is responsibility of the system
integrator.
GVO-CLP-SR/FS actuator is intended to be part of the final element subsystem as defined
per IEC 61508:2010. The achieved SIL level of the designed function must comply with the
project specification and must be submitted to the system integrator.
The final control element subsystem needs to be sized properly to assure that its operating
time is equal or less than the time required to reach a safe state.
GVO-CLP-SR/FS actuator will move the valve to its safe state in equal or less than the
required SIF’s response time under the specified conditions.
