November 2017
SIL Safety Manual
SM-025-GVO Rev. 0
8
Section 4: Product Description
Product Description
4.2
GVO-CLP-SR/FS working principle
Emerson GVO-CLP-SR/FS actuator working principle is simplified in the following Figure 2.
In the normal operating situation the operating fluid (instrument air, nitrogen or sweet gas)
is supplied to the actuator’s open (close) chamber of the pneumatic cylinder: the cylinder
piston stroke causes the actuator operation and the consequent valve movement to the open
(close) operational position, and at the same time compresses the spring. Upon a demand,
the instrument air is discharged from the open (close) chamber of the cylinder: the actuator
performs the closing (opening) operation driven by the spring, and the valve moves from the
open (close) position to the close (open) position (safety-related position).
Figure 2
GVO-CLP-SR/FS actuator simplified working principle
PNEUMATIC CONNECTION
