16
• Id.Nr.: 229224-9
District heating tank FSN and FSN-E
17. Domestic Hot Water Side Connection (pressure resistant)
F
In cases in which unsuitable or non-functional storage tank connection fittings are used as well as
in cases in which the stated operating pressure is exceeded, we shall refuse to guarantee the water
heater in any way whatsoever.
All water heaters that display a nominal pressure of 6 bar (ATO or kp/cm
2
) on their rating plates
are pressure resistant storage tanks and can be connected pressure-tight at a mains pressure of
up to 5.5 bar (ATO).
If the system pressure is higher then a pressure reduction valve must be
installed in the cold water input pipe.
The water connection must only take place via a certified membrane safety valve or a membrane safety
valve combination - connection fitting for pressure resistant storage tanks.
A safety valve combination consists of shut-off, back-flow, drainage and safety valves with expand-
able water outlet and is installed between the storage tank's cold water inlet pipe (blue) and cold
water inlet in an
appropriate sequence
.
As a general rule the following is to be noted:
In order to ensure the faultless functioning of the connection fittings these may only be installed in
frost-protected spaces. The outlet of the safety valve must be open and observable and/or the outlet
pipe from the drip tray (water overflow funnel) must not terminate outside so that neither frost nor
blockages due to dirt and the like can result in a malfunction. Care must be taken to ensure that the
drip container is not blocked.
Furthermore, care must be taken to ensure that the outlet pipe of the safety valve is installed with a
constant incline.
No shut-off valve or any other restriction may be installed between the safety valve and the storage
tank cold water inlet.
The safety valve must be configured for a trigger pressure that is lower than the nominal pressure (6
bar) of the storage tank. Before the final connection of the storage tank the cold water inflow pipe
must be flushed through.
Once the water has been connected and the storage tank has been filled without air bubbles, the
function of the connection fittings must be checked.
a) In order to avoid a blockage of the safety valve's venting mechanism as a result of lime-scale
depositing, the safety valve's venting mechanism should be operated from time to time dur-
ing the operation of the system. It should be observed whether or not the valve re-closes after
releasing the venting mechanism and whether or not the queued water is drained off completely
Drainage Valve
Safety Valve
Back-flow Valve (Return-flow Inhibitor)
Test Valve
poss. Pressure Reduction Valve
Shut-off Valve
User Fittings
