65
In case the two-way safety device has responded to refill with water not conforming to
Č
SN 07 7401
it is necessary to treat the water in the system so that it again conforms to this standard
Installation
Only the professionally qualified person is allowed to carry out the installation. It is always necessary to
observe the conditions specified for two-way safety valve installation and follow the flow directions indicated
on the valve body in order to guarantee its proper function. The safety valve is always installed in the boiler
outlet piping or directly on the boiler in its upper part where the heated water leaves boiler and flows into
heating system. When the valve is installed it must be checked whether by using ¾“ sleeve that can be both
in piping and on the boiler it is ensured that the valve thermostatic element will be fully immersed after the
installation. After the mounting in the sleeve the downpipe is connected at the point „C“ (Fig. no. 31) and hot
water from boiler will flow into drain through this downpipe. The cooling water inlet is connected at the point
“A” according to (Fig. no. 32) and this water will ensure cooling of boiler after the valve has been put into
service. Filter for catching the mechanical impurities must be mounted at cooling water inlet. The piping that
according to Fig. no. 32 is led into return pipe of the heating system near the boiler is connected at the point
“B”.
Regular maintenance
Turn the safety valve head once a year in order to remove possible impurities deposited in the valve.
Clean the filter at cooling water inlet.
Important
The flows cannot be reversed therefore the filling and draining indicated on the valve must be observed.
In case of using an open expansion tank the safety device against overheating needn’t be used.
Every heat source in an open heating system must be connected with an open expansion tank positioned
at the highest point of the heating system. The expansion tanks must be dimensioned in the way making
sure that their capacity is sufficient for holding varying water volumes caused by heating and cooling.
The open expansion tanks must be equipped with not closable breather and overflow pipes. The overflow
pipe must be designed in such a way that it will safely drain the maximum flow volume entering the system.
This can be reached by dimensioning the overflow pipes by one DN higher than the filling pipe. The
expansion tanks and their connecting pipes must be designed and positioned at the places where they are
reliably prevented from freezing
Fig. no. 33 Examples of open expansion tanks connection
7.2 Control activity before start
Boiler only can be put into service by a contractual service organization qualified for this activity
performance.
Following checks must be carried out before putting the boiler into service:
a) Filling the heating system with water (pressure gauge check) and tightness of the system;
b)
connection to the chimney
- it must be approved by a chimney-sweepers’ company(chimney
revision);
c) draught regulator and thermostatic valve functionality;
1 Heat source
2 Expansion tank
3 Safety pipe
4 Expansion pipe
5 Overflow pipe
6 Filling pipe
7 water level limiter
8 Return pipe
