Wholesalercat_APA_2012_LOW-complete - page 67

65
m
3
/h
AVTA thermostatic valve - sizing
Valve flow quantity in fully open position, as a function of pres-
sure drop Δp.
With fully open valve the differential pressure should be around
50% of the total pressure drop across the cooling system.
Nomogram showing the valve k
v
range.
k
v
values are always given for water flow
in m
3
/h with a pressure drop Δp of 1 bar.
The valve should be selected so that the
necessary k
v
value lies in the middle of the
regulation range.
Example: AVTA 10 and 15 are the most suit-
able for a k
v
value of 0.7
Relation between water quantity and pressure drop across valve.
Example: Flow 0.85 m
3
/h with a pressure drop of 1.5 bar.
The k
v
value becomes 0.7 m
3
/h.
Heating or cooling with water.
Example: Necessary cooling output 10 kWwith Δt = 10°C.
Required flow 0.85 m
3
/h.
bar Pressure drop across valve
Capacity with fully open valve
1...,57,58,59,60,61,62,63,64,65,66 68,69,70,71,72,73,74,75,76,77,...172
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