Dražice OKC 100 NTR Operation And Installation Manual page 19

added to the system. No stop valves can be put between the heater and the safety valve.
During the 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 common operation, such a check needs to be
implemented at least once a month, and after each heater shutdown for more than 5 days.
Water can drip from the safety valve through the drain pipe; the pipe must be freely open to
the atmosphere, placed vertically and shall be in an environment free of temperatures below
freezing. When draining the heater, use a drain valve. You must first close the water supply
to the heater.
Required pressures – Table 10. We recommend that the hot water distribution from the heater was as
short as possible to minimise heat losses.
ADMISSIBLE
SAFETY VALVE OPERATING
STARTING OVER-
PRESSURE PRESSURE OF
[MPa] WATER
HEATER [MPa]
0.6
0.7
1
Table 10
MAXIMUM
PRESSURE IN
COLD WATER
PIPES [MPa]
0.6 up to 0.48
0.7 up to 0.56
1 do 0.8
- 19 -