Plumbing Fixture - Dražice OKC 100 NTR Operation And Installation Manual

2.3 PLUMBING FIXTURE

For potential disconnection of the heater, the service water inlets and outlets must be
provided with screw coupling Js 3/4" (Figure 11, Figure 12, Figure 13). If the hot service
water (HSW) distribution is equipped with circulation circuit, the reverse pipe is connected to
the inlet identified as CIRCULATION. The 100, 125, 160 NTR and 100, 125, 160 NTR / HV types
are equipped with a discharge outlet. In 200 and 250 NTR(R) types, the HSW inlet has to be
provided with a "T" fixture with a drain valve. For operation, the heater must be equipped
with a safety valve. Safety valve is mounted on the cold water inlet identified with a blue
ring.
Each hot service water pressure heater must have a safety valve with a membrane spring.
The safety valve must be easily accessible, as close to the heater as possible. The input pipes
must have at least the same clearance as the safety valve. The safety valve is placed high
enough to secure dripping water drain by gravity. We recommend mounting the safety valve
onto a branch pipe. This allows easier exchange without having to drain the water from the
heater. Safety valves with fixed pressure settings from the manufacturer are used for the
assembly. Starting pressure of a safety valve must be identical to the maximum allowed
heater pressure, and at least 20% higher than the maximum pressure in the water main –
see Table 10. If the water main pressure exceeds such value, a reduction valve must be
Figure 10
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