Navien NCB-190/060H, Руководство по установке и эксплуатации

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31 Installing the System Piping
3.6 Considerations for System
Applications
Read and follow the guidelines listed below when
installing system piping for the Navien NCB-H boiler:
●
System application drawings are intended to
explain the system piping concept only.
●
For the upstream side of all pumps, use straight
pipes with a minimum inside diameter of
1 /
2
in (12 mm).
●
Provide a system expansion tank following the
guidelines on page 21.
●
Installations must comply with all local codes.
In Massachusetts, a vacuum relief valve must be
installed in the cold water line per 248 CMR.
Air Removal
The boiler and system piping layout must be
configured to promote the removal of air from the
system. Air vents and bleeders must be strategically
placed throughout the system to aid in purging the
air from the system during commissioning of the
boiler. The system must also employ the use of an
air removal appliance, such as an air separator or an
air eliminator designed to remove the air from the
water as it flows through the system.
Follow the installation instructions included with
the air removal appliance when placing it in the
system; air removal appliances generally work better
when placed higher in the system. Always locate
air removal appliances in areas of the system that
have a guaranteed positive pressure, e.g., in close
proximity to the water fill and expansion tank.
Expansion Tank
The expansion tank must be sized in accordance
with the water volume of the system as well as the
firing rate of the appliance. It is important to locate
the expansion tank, and make-up water connection,
on the inlet side of any pump in the system, as
doing so will guarantee the lowest pressure in the
system will be at least equal to the tank and make-
up water pressure.
Ensure the expansion tank cannot become isolated
from the boiler anytime the system is operating.
Failure to follow these instructions may lead to
discharge from the pressure relief valve, which may
result in property damage or injury.
2. Loosen the manual and automatic air vents and
the boiler drain valve.
3. Fill the boiler to the correct system pressure.
The correct pressure will vary with each
application. The typical cold water fill pressure
for a residential system is 12 psi. The operating
pressure must never exceed the relief valve
pressure setting.
4. At initial fill and during boiler start-up and
testing, check the system thoroughly for leaks.
Repair any leaks before proceeding further.
WARNING
Eliminate all system leaks. The continual
introduction of fresh makeup water will reduce
boiler life. Minerals can build up in the heat
exchanger, reducing heat transfer, overheating
the heat exchanger and causing heat exchanger
failure.
The system may have residual substances that
could affect water chemistry. After the system has
been filled and leak tested, verify that water pH and
chlorine concentrations are within the acceptable
range by performing sample testing.
CAUTION
Before operating the boiler for the first time,
ensure that the boiler system is filled with water.
Purge the air inside the system to avoid damage
to the boiler.