User Guide

Technical Instructions Flowrite VF 599 Series Three-Way Valves
Document Number 155-185P25
April 9, 2007
Page 8 Siemens Building Technologies, Inc.
VF0165R1
A
2W NC &
3W Upper
2W NO &
3W Lower
B
Line Size (in)
1400
1200
1000
800
600
400
200
0
1600
250
200
150
100
50
25
0
1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
Differential Pressure (psi)
Differential Pressure (kPa)
Line Size (in)
1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
250
200
150
100
50
25
0
Differential Pressure (psi)
1400
1200
1000
800
600
400
200
0
1600
Differential Pressure (kPa)
VF0280R1
4-inch Pneumatic
8-inch Pneumatic
12-inch Pneumatic
SQX
EI/Mech Low Force
SKD
SKB
Rack & Pinion Valve
Line Size (in)
1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
Line Size (in)
1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
250
200
150
100
50
25
0
Differential Pressure (psi)
1400
1200
1000
800
600
400
200
0
1600
Differential Pressure (kPa)
250
200
150
100
50
25
0
Differential Pressure (psi)
1400
1200
1000
800
600
400
200
0
1600
Differential Pressure (kPa)
Figure 4. Close-off Pressures.
Operation
As the valve stem moves downward, the flow
through the NO port decreases and the flow
through the NC port increases. As the valve stem
moves upward, the flow through the NO port
increases and the flow through the NC port
decreases.
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.
VF0163R1
NC
NO
COM
Figure 5.