Flow Characteristics - CALEFFI ThermoSetter 116 Series Installation, Commissioning And Servicing Instructions

Flow characteristics

The ThermoSetter thermostatic balancing valve is designed to balance
individual branches of domestic hot water recirculation systems, based
on the temperature at the valve. It automatically modulates flow to
maintain hot water availability to all fixtures in the branch circuit.
The valve is at minimum flow (Cv = .23) when the incoming water
temperature is equal to the set-point position of the adjustment
dial. The valve opens as incoming water temperature drops.
For pressure loss calculations in the recirculation system, follow
traditional pipe sizing and head loss practices. For pressure loss
calculations across the ThermoSetter valve, use the design curve
shown in the graph below. This line represents a typical valve position
under normal working conditions (∆T= 10°F). Determine the pressure
drop across the valve by selecting the branch design GPM on the
graph X-axis, draw a vertical line up to the "design" curve, then
go across to the Y-axis to find the design pressure drop. Include
that pressure drop in your head loss calculations for the circuit.
14.5
10
7.25
6
5
∆p (psi)
4
3.00
2.00
1.50
1.00
0.70
0.50
0.30
0.20
0.15
0.10
0.07
0.05
0.03
0.02
0.01
The "by-pass mode" curve in the chart above shows the head loss of
the valve when it is in by-pass thermal disinfection mode for Legionella
control.
10˚F ∆T
inlet to setpoint
0.23 Cv
minimum
0.52 Cv
design
1.2 Cv
by-pass
2.1 Cv
full open
Operation in
by-pass mode
8
∆p (kPa)
20
13
11
7.0
3.5
2.0
1.4
1.0
0.7
0.5
0.3
0.2
0.1
3 4.5 6 7 8.810 11
2. 5