BaltGaz NEVALUX-8230 User Manual page 49

Guidance to select an expansion membrane tank
Selecting an expansion membrane tank in case of using water as a heat carrier
In case of connecting the boiler to the heating system with a volume of more than 70 liters, it is necessary to install an additional expansion membrane tank, connecting it to the
return heating line really close to the boiler.
In the tables presented below, you can find water volume necessary for filling the elements of the heating system. The volume of the boiler by itself is 2 liters. This data allows
to make an approximate calculation of the water quantity in the heating system to which the boiler will be connected.
TABLES FOR WATER VOLUME CALCULATION:
Copper pipes
Pipes diameter, Water quantity,
mm l/m p.
10х0,8
0,05
12х1,0
0,08
15х 1,0
0,13
18х 1,0
0,20
22х1,2
0,30
28х1,2
0,52
35х1,5
0,80
42х1,2
1,20
after filling the system with water.
the vessel.
system. Measuring this height in meters, we calculate static pressure taking 0, 01 MPa of overpressure for each height
meter. Initial pressure in the expansion tank should be approximately 10% more than calculated static pressure.
pressure in the expansion vessel should be approximately (8х0,01) х 1,1=0,09 MPа. To sum up, calculated pressure is
considered as initial one in the heating system with cold water.
.
Steel pipes
Pipe Water quantity,
diameter, mm l/m p.
G3/8 0,13
G1/2 0,21
G3/4 0,38
G1 0,60
G11/4 1,02
G11/2 1,39
G2 2,21
G21/2 3,72
G3 5,13
G4 8,71
Another way to determine water volume in the heating system is to compare values of the water sensor before and
Minimal initial pressure in the expansion tank should not be less than the static pressure at the connection point of
Static pressure is a pressure of the water column between the expansion vessel and the highest point of the heating
Example: Measured height is 8 meters, which corresponds to the value of the static value 0,08 MPа. Initial
Water volume in the radiators
Radiator type Power,Wt
Cast-iron:
500/160 130
ТА-1
150
Т-1
125
Steеl:
11-400/960 915
11-600/960 1282
22-600/960 2225
11-600/1000 1310
22-600/1000 2225
11-600/900 1179
22-600/900 1984
11-590/960 1091
22-590/960 1908
The power is indicated for the parameters 90/70/20 °С, where:
90 –temperature in the direct heating line;
70 – temperature in the reverse heating line;
20 – temperature in the premise
56
Volume, l
For 1 gill
1,01
1,34
1,18
For a radiator
2,78
4,15
8,30
2,97
5,93
3,10
6,30
3,20
6,50
Annex II