Data Sheet for Product

4/10
Siemens MiniCombiValves (MCV) CE1N2185en
Smart Infrastructure 2020-01-09
Engineering notes
The MiniCombiValves allow preadjustment of the required volumetric flow
V

. This
preadjustment is made by limiting the valve's stroke.
With the MiniCombiValve, the adjusted value represents the maximum flow rate be-
cause the integrated pressure controller maintains the volumetric flow at a constant
level, even if the differential pressure varies between 0.1 and 2 bar. For this reason,
central precontrol of the pressure is not required, and the valve's authority need no
longer be considered.
The water must be free from organic substances.
The valve is to be sized based on the volumetric flow
V

resulting from the required
radiator output.
Basis of design
1. Ascertain heat demand Q in W
2. Determine temperature differential ΔT in K
3. Volumetric flow
Δtc
Q
V
.

=






=
 h
l
3600
KK)(J/kg
W
V

= volumetric flow l/h c = specific heat capacity J/kg x K
Q = heat demand W ΔT = temperature differential K
Example
1. Heat demand
Q

= 2800 W
2. Temperature differential ΔT = 20 K
3. Volumetric flow






=

=
h
l
120.373600
204187
2800
V

Result
With this calculated value and a Δp
V100
= 100 kPa, the required type of valve can be
determined from the following preadjustment table or from the sizing chart (page 5).
• In this example, the ideal valve would be VPD / VPE..B-120 with a factory setting of
3
• Valve type VPD / VPE..A-90 is possible also, but the preadjustment must be appro-
priately changed
• Valve type VPD/VPE..A-145 is theoretically also possible, but the stroke is very
short then.
Recommendation therefore: The valves should operate at a preadjustment of 3 or
higher.
Engineering example