p. 27/69
boiler is cooled to the ambient temperature. This precautions are induced
due to prevent rising of thermal stress of the steel boiler’s body and its
damage (leakage);
•
The water, utilized for filling purposes of the heating system should be
decontaminated and air-free, and is not dedicated for any other purposes,
but as a circulating fluid only. Any heating system drainage is
inadmissible, except when repairing modules/sections of the system;
•
In case that the heating system is equipped with closed expansion vessel,
then it should be known, that these systems are under pressure and
practically do not allow direct contact between the circulating fluid and
the ambient air. These systems are not threatened by oxygen absorption.
However, these systems are pressurized and their pressure should be
monitored and controlled if necessary, in order to ensure safe system
operation – both the pressure rising could be dangerous, as the
mechanical loads of some of the heating system elements gets higher, as
well as the lower pressure levels could lead to air penetration, even air
suction through small invisible cracks in thermally loaded elements,
which will lead to intensive corrosion. That’s why during the heating
period, it is necessary to check the circulating water pressure periodically
and drain or fill if needed. Please pay attention and do not allow air
penetration in the heating systems at fill-up process. The circulating water
should be utilized only for heating purposes. It is not recommended to
drain the circulating water out of the system, except in case of repair
works. It is recommended to check and control the water pressure at
systems heating up process, as well as on a 14 days period. If water fill-up
is needed, then the fluid should cover the requirements, described above;
•
It is not allowed in any cases to fill the operating boiler with cold water,
as this could lead to thermal stresses and could eventually damage the
unit. Fill the boiler with additional water only when it is cooled down to
ambient temperature;
•
In case that the boiler as well as the heating installation will not be in
exploitation for a long period, then in order to prevent local water
freezing and damages, it is advisable to perform total drainage of the
circulating water. Please take into account that the presence of liquid in
the heating system, as well in the boiler will prevent oxidation process of
the metal surfaces, corrosion and system failures;
