Product Overview

Data sheet STV Series
Balancing Valves
VDDNB122 © Danfoss 05/08
Flow Rate Graphs:
STVA Balancing Valves 2-1/2” - 6”
Selection example:
Required- A flow rate of 222 GPM (14 l/s) and a pressure drop of 1.67 FOH (5 kPa)
The required balancing valve for this application is a 5” with a setting of 7.8 turns or a 6” with a
setting of 5.8 resulting in a Cv of 263 (Kv=225).
1 foot of head (FOH) = 0.434 psi
1. Plot the required flow rate
and pressure drop within the
columns and then draw a
line between these plotted
points.
2. Draw an additional
horizontal line from the
intersection of the Cv
column across the valve
sizes.
3. Based upon the intersection
of the horizontal line with
the valves sizes, select the
appropriate sized valve.
In selecting the valve, a margin
of allowance for adjustment
should be considered if during
commissioning the pressure
drop is lower than designed.
This reduced pressure drop may
result in an undersized valve.
The selection of a valve that has
a pre-set value above 3 turns
offers better accuracy when
setting.
Flow Rate C
v
/ K
v
Number of Turns
Opened
Pressure Drop
Valve Size
5