Radijator Inženjering d.o.o, 36000 Kraljevo, Živojina Lazića - Solunca br.6, Srbija
tel. +381 36 399 140, fax. +381 36 399 150, http://www.radijator.rs
e-mail: [email protected]
45
Safety valve must have the identification plate with following information:
- the name of the manufacturer
- mark of the safety valve type / year of testing
- nominal flow
- data on the calibrated thermal output of the safety valve
- the highest opening pressure i.e. 3 bar
In prescribed periods of time it is necessary to check the proper operation and to perform
recalibration by certified companies. These obligations will be done according to the law of the
country in which the boiler is installed. It is obligatory to keep written document with data from
last calibration of the safety valve.
At least one more safety pressure valve needs to be installed on the return line.
Flow out valve for thermal safety (
Figure 5
)
Figure 5. Thermal safety valve
This safety element also has the role to limit the temperature. In the following text it is marked by
abbreviation VTO.
In some extremely dangerous situations, the transformation of water to steam is such that safety
pressure valves are not sufficient to provide for the safety of the hydraulic system. Due to this
reason, the installation of the VTO is obligatory. Depending on legal regulations in countries in
which the boiler is installed, VTO must be installed only for powers greater than prescribed or
VTO must be installed for all powers.
Place for installation is shown in the installation diagram for the boiler and
in
Figure 6
.
Cold sanitary water is fed to the VTO. When the probe in VTO has the information that the
temperature is over 95 degrees, VTO opens and the water passes through the copper spiral.
After some time, the temperature of the water in the boiler returns to normal.
One connection of the spiral is used for VTO and the other for letting out the water which has
passed through the spiral. It does not matter which connection of the spiral is for VTO and
which for letting out the water. It is obligatory to observe the instructions for installation which
the manufacturer of VTO has given.
