Product Overview

Insulation shells
The 142 series balancing valve can be supplied with optional insulation shells,
code CBN142xxxx series purchased separately, to minimize heat loss or elim-
inate condensation in chilled water applications.
Code Size
CBN142241A Fits ½"
CBN142251A Fits ¾"
CBN142261A Fits 1"
CBN142271A Fits 1¼"
CBN142281A Fits 1½"
USING AND SETTING THE BALANCING VALVE
Measuring the flow rate
The 142 series balancing valves contain pressure test ports located upstream and downstream of the valve plug. As fluid flows through the valve and past
the adjustment plug, a differential pressure across the two ports is induced. By measuring this differential pressure value and knowing the flow coefficient
of the valve (corresponding to the knob position) the flow rate can be determined.
When fluid medium is water
When the fluid is water, the flow rate can be determined by either referencing the flow characteristics chart for the respective valve size, or by using the
formula
G = Cv ∙ √∆P where G is the flow rate in gpm, Cv is the flow coefficient of the balancing valve, and ∆P is the pressure differential in psi.
Example (see graph on next page), for balancing valve code 142251A (¾") with the knob position set to position #2, and the differential pressure measured
to be 3.0 psi, find the point on the chart where the 3.0 psi value intersects the position #2 line. Drop a line vertically to intersect the gpm axis and estimate
the corresponding flow rate to be 3 gpm. Alternately, we can determine the flow rate G by substituting the values into the above formula: G = 1.7√3 = 3 gpm,
where 1.7 is the value Cv at position #2.
When fluid medium is other than water
A correction factor for calculating flowrate needs to be applied when using fluids with viscosities similar to water (which is the case for most glycol and
salt based anti-freeze solutions).
G
A
= , where G
A
is the actual flow rate of the fluid, G is the calculated value from the chart or formula, and SG
F
is the specific gravity of the fluid.
For example, if a 50% polypropylene glycol solution is the medium instead of water, we must first determine the specific gravity, which is 1.04. The actual
flow rate can be the calculated as:
G
A
= = = 3/1.02 = 2.94 gpm.
G
SG
�
F
G
SG
�
F
3.0
1.04
�