- 10 -
2.3
PLUMBING FIXTURE
Power water connects to pipes with ¾“ thread in the bottom part of the reservoir. Blue - cold
water supply, red – hot water outlet. For potential disconnection of the tank, utility water inlets
and outlets must be provided with Js 3/4“ screw coupling. The safety valve is mounted
on the cold water inlet identified with a blue ring.
Every hot utility water pressure tank shall be equipped with membrane spring loaded with safety
valve. Nominal clearance of safety valves is defined by standard. Tanks are not equipped
with safety valve. Safety valve shall be easily accessible, fitted as close as possible to the tank.
The inlet pipes must have at least the same clearance as the safety valve. Safety valve is placed
high enough to secure dripping water drain by gravity. We recommend mounting the safety
valve onto a branch pipe. Easier exchange without the necessity of draining water from the tank.
Safety valves with fixed pressure settings from the manufacturer are used for the assembly.
The starting pressure of the safety valve must be identical to the maximum allowed pressure
of the tank, and at least 20 % higher than the maximum pressure in the water main (Table 4).
If the water main pressure exceeds such value, a reduction valve must be added to the system.
No closing armature may be mounted between the tank and the safety valve. During assembly,
follow the guide provided by the safety equipment manufacturer.
It is necessary to check the safety valve each time before putting it into operation. It is checked
by manual moving of the membrane from the seat, turning the make-and-break device button
always in the direction of the arrow. After being turned, the button must click back into a notch.
Proper function of the make-and-break device results in water draining through the safety valve
outlet pipe. In regular operation, such a check needs to be carried out at least once a month,
and after each shutdown of the tank longer than 5 days. Water may be dripping off the drain
pipe of the safety valve; the pipe must be open into the air, pointed down; environment
temperatures must not drop below zero. When draining the tank, use the recommended drain
valve. First of all, close water inlet in the tank.
Find necessary pressure values in the below Table 4. For proper safety valve operation, a backflow valve shall
be mounted on the inlet pipes, preventing spontaneous heater draining of the tank and hot water
penetration back into the water main. We recommend that the hot water distribution from the tank was as
short as possible to minimise heat losses. At least one demountable joint must be mounted between the tank
and every supply pipe. Adequate piping and fittings with sufficiently dimensioned maximum temperature
and pressure values must be used.
Table 4
SAFETY VALVE START-
UP PRESSURE [MPa]
ACCEPTABLE
OPERATING OVER-
PRESSURE OF WATER
TANK [MPa]
MAXIMUM PRESSURE
IN COLD WATER PIPES
[MPa]
0,6
0,6
to 0.48
0,7
0,7
to 0.56
1
1
to 0.8
