Setting the pressure for the expansion vessel
p
0
Before filling the system with water, check and set the pressure
p
0
.
The expansion vessel is
factory set to the pressure specified on the standard label. For correct operation of the system,
set the pressure
p
0
according to the equation below. The filling must not exceed the maximal
operational pressure specified on the serial label of the expansion vessel.
Calculate the
p
0
pressure value with the help of the equation:
ሾMPaሿ =
ுሾ୫ሿ
ଵ
+ 0,02 ሾMPaሿ
,
ቀ
ሾbarሿ =
ுሾ୫ሿ
ଵ
+ 0,2 ሾbarሿቁ
.
CAUTION
If the calculation shows a pressure lower than 0,1 MPa (1 bar), set the pressure of the
expansion vessel to 0,1 MPa (1 bar).
p
0
[MPa (bar)] – pressure in the expansion vessel,
p
0min
[MPa (bar)] – minimal allowed pressure of the heating system,
p
0max
[MPa (bar)] – maximal allowed pressure of the heating system,
H
[m] – Height of the heating system.
Set the amount of pressure in the expansion vessel by releasing or supplementing dry nitrogen.
Record the new value of the pressure
p
0
on the serial label.
Open the ball valveof the expansion vessel carefully, open the vents and close the drain.
Filling the heating system
Use the filling valve to fill the system with water of suitable quality (with anti-corrosion additives,
etc.) to the pressure
p
F
.
ி
ሾMPaሿ =
ሾMPaሿ + 0,03 ሾMPaሿ
,
ሺ
ி
ሾbarሿ =
ሾbarሿ + 0,3 ሾbarሿሻ
.
p
F
[MPa (bar)] – filling pressure,
p
0
[MPa (bar)] – pressure in the expansion vessel.
Filling the system to the final pressure
The final pressure of the system is determined by heating the system to the maximal heating
temperature (thermal degassing).
Turn off the circulation pumps, open the vents and vent the system.
Fill the system up to the final pressure which is 0,05 MPa (0.5 bar) lower than the venting
pressure of the safety valve.
ሾMPaሿ ≤
ୱ୴
ሾMPaሿ − 0,05 ሾMPaሿ
,
ሺ
ሾbarሿ ≤
ୱ୴
ሾbarሿ − 0,5 ሾbarሿሻ
.
p
E
– the final pressure of the system,
p
SV
– the pressure of the safety valve.
