VVVP445…and VXP45… Series Two-port and Three-port Seat Valves
Technical Instructions
ANSI Class 250
Document Number CM1N4845E-P25
Rev. 4, February, 2002
Siemens Building Technologies, Inc.
Page 3
Sizing
Water Sizing Equation:
p
Q
C
v
∆
=
Where:
C
v
= Flow Coefficient
Q = Volumetric flow rate (gpm)
∆
p = Pressure drop, psi
Warning/Caution
Notations
WARNING:
Personal injury, or loss of life may
occur if you do not follow the
procedures as specified.
CAUTION:
Equipment damage, or loss of data
may occur if you do not follow the
procedures as specified.
Control
Characteristics
0,8
1
0,6
0,4
0,2
0
0
0,2 0,4 0,6 0,8
1
H
0
H
100
V
100
B
AB
A
AB
AB
A
B
SV
AL0067R1
Legend:
V
100
= Volumetric flow rate
H
0
= Valve stroke 0% = Path A
→
AB closed,
bypass B opened
H
100
= Valve stroke 100% = Path A
→
AB opened,
bypass B closed
Tor AB
= Constant total flow from A and B
→
AB
Tor A
= Variable flow in straight-through path
from A
→
AB
Tor B
= Variable flow in bypass-through port
from B
→
AB
CAUTION:
The VXP45…can only be used as mixing valves.
Engineering Notes
Recommendation
Valves VVP45… and VXP45… are preferably installed in the return, as this provides
lower temperatures on the seals.
Provide strainer upstream of the valve inlet.
AB
A
AB
A
SV
AL0069R1
Figure 1. VVP45.
Two-port valves VVP45…
Flow permissible only in direction
of arrow from A
→
AB arrow on
valve body.
AB =
Variable flow in straight-
through
port
(outlet).
A =
Variable flow in straight-
through
port
(inlet).
Stem retracted: Path A
→
AB
open.
Stem extended: Path A
→
AB
closed.
