COLD
HOT
MIX
COLD
HOT
MIX
Operating principle
The controlling element of the three-way
thermostatic mixing valve is a thermostatic
sensor fully immersed in the mixed water
outlet tube which, as it expands or contracts,
continuously establishes the correct proportion
of hot and cold water entering the valve. The
regulation of these flows is by means of a
piston sliding in a cylinder between the hot
and cold water passages. Even when there
are pressure drops due to the drawing off of
hot or cold water for other uses, or variations
in the incoming temperature, the thermostatic
mixing valve automatically regulates the water
flow to obtain the required temperature.
COLD
HOT
MIX
Inlet port check valve detail for 521 “AC” models
Flow curve
Flow should never exceed standards for pipe size and materials
.
Kv = 2.6
0.
1
10
0.023
0.23
0.046
0.069
0.02
0.05
0.
2
0.
5
0.115
2.3
0.46
0.69
1.15
20
50
∆
p
(ft of head)
G
(l/min)
(gpm
)
23
4.6
6.9
11.5
46
0.01
0.1
0.02
0.03
0.05
1
0.2
0.3
0.5
(psi) (bar)
10
2
3
5
20
1
0.
1
0.2
0.5
0.0
5
10
2
5
20
0.001
0.01
0.002
0.003
0.005
0.1
0.02
0.03
0.05
1.0
0.2
0.3
0.5
Cv = 3.0
9.2
0.092
0.92
0.04
0.4
4
0.004
0.04
0.4
50
115
161
50
70
2.0
5.0
190
70
100
140
4
