INSTALLATION, OPERATION AND MAINTENANCE MANUAL
BiSolid Saver OM-BSSV00/08/2012/EN
42
Figure 18. Fixing the middle cover panel
5, 6
3
7.8. EXPANSION TANKS (BUFFERS) OPERATION AND
INSTALLATION
The usage of expansion tanks (buffers) in systems for floor and central heating has a lot of
advantages, mainly because they limit the intake of air in the heating system. Increased
pressure has been monitored in some systems with expansion tanks, caused by incorrect
calculations. After years of boiler tests there has been introduced a common method for
calculation of expansion tanks sizes, with suitable maximum hydraulic difference which can
not damage the boiler body in cases of dynamic loads. For steel made boiler this difference is
defined at 50 kPa. For installation of expansion tanks to steel hot water boilers with capacity
up to 50 kW, the below introduced principles must be considered. In case any of the
principles is not considered the manufacturer will not cover warranty claims, for boilers that do
not function due to incorrectly designed, calculated or installed expansion tank.
1. The expansion tank water supply pipe must be as shortest as possible, without shut-off
devices and with availability for expansion. The expansion tank has to be positioned
without possibility for heating from sun light.
2. Every heating system must be equipped with minimum one reliable safety valve,
installed on the boiler outlet pipe line, and also with pressure-gauge.
3. If a safety valve is installed it is necessary to perform additional check for its working-
order, which can be controlled by checking the overpressure value 180 kPa, at which
point it actually opens. In case the safety valve opening pressure is higher, a new
adjustment must be performed.
4. Installation and adjustment of the safety valve, as well as installation, with accompanying
checks and correction of the gas volume in the expansion tank, must be performed only
by an authorized for such activity company. Before filling the heating system with water it
is necessary to ensure that the gas pressure in the expansion tank is higher than the
system hydrostatic height.
5. The heating source must be equipped with safety device, by the means of the European
norms. For the solid fuel boilers with heat capacity up to 50 kW is necessary to install a
draught regulator. The maximum allowed operation temperature is limited to 95
o
C.
6. The expansion tank and its water supply pipe must be secured against water freezing.
