User Guide

Technical Instructions Flowrite 599 Series Two-Way Valves, 1/2 to 2-Inch, Bronze Body, ANSI 250
Document Number 155-184P25
August 25, 2009
Page 10 Siemens Industry, Inc.
ELECTRONIC PNEUMATIC
Figure 4. Close-off Pressures.
Operation
Figure 5 shows the normally open valve in
the open or full flow position and the
normally closed valve in the closed or zero
flow position. The actuator spring provides
the necessary force to hold the stem in the
raised or normal position.
In the event of power failure, a spring
return actuator returns the valve to its
normal position. Non-spring return
actuators will hold the last commanded
position. See the Technical Instructions of
the various actuators for additional
information.
Figure 5.