Drazice OKC 250 NTRR/SOL Operating And Installation Manual - Page 12
Browse online or download pdf Operating And Installation Manual for Boiler Drazice OKC 250 NTRR/SOL. Drazice OKC 250 NTRR/SOL 17 pages. For solar systems
Also for Drazice OKC 250 NTRR/SOL: Operation And Installation Manual (12 pages)
Print Page
2.3 PLUMBING FIXTURE
Every hot utility water pressure tank shall be equipped with membrane spring loaded
with safety valve. Tanks 300 l are not equipped with safety valve. If the tanks 200 and 250 l
enclosed safety valve 0.6 MPa. 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 tank pressure, and at least 20 % higher than the maximum
pressure in the water main. If the water main pressure exceeds such value, a reduction valve
must be added to the system. During assembly, follow the guide provided by the safety
equipment manufacturer. The cold water inlet of each individually closable heater must be
fitted with a seal, test tap or plug to check the non-return valve, as well as a non-return valve
and safety valve. Heaters with a volume of more than 200 litres must also be fitted with
a pressure gauge.
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 that prevent spontaneous 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.
SAFETY VALVE
START-UP
PRESSURE [MPa]
0.6
0.7
1
Table 4
ACCEPTABLE OPERATING
OVER-PRESSURE OF WATER
TANK [MPa]
0.6
0.7
1
MAXIMUM
PRESSURE IN COLD
WATER PIPES [MPa]
up to 0.48
up to 0.56
up to 0.8
- 12 -