Water Piping; System Sizing - NORITZ AMERICA CORPORATION NH199-DV Manuel D'installation Et Mode D'emploi

9.

Water Piping

This appliance is suitable for space heating applications. Do not use this appliance if any part has been underwater.
Immediately call a qualified service technician to inspect the appliance and replace any part of the control system and
gas control which has been under water.
A relief valve that is rated in accordance with and complying with The ANSI/ASME Boiler and Pressure Vessel Code,
Section IV ( Heating Boilers ) must be installed on the left side of the case. A pressure relief valve, fitting, and gasket
is provided with this boiler and should be installed as shown below. This pressure relief valve must have the hourly
rated temperature discharge capacity (199,900 Btuh for the NH199-DV, 150,000 Btuh for the NH150-DV). The relief
capacity must not exceed 30 psi. No valve shall be placed between the relief valve and the boiler. The relief valve
must be installed such that the discharge will be conducted to a suitable place for disposal when relief occurs. No
reducing coupling or other restriction may be installed in the discharge line. The discharge line must be installed to
allow complete drainage of both the valve and the line. If this unit is installed with a separate storage vessel, the
separate vessel must have its own temperature and pressure relief valve. This valve must also comply with The
Standard for Relief Valves and Automatic Gas Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22. (in the
U.S. only). A temperature relief valve is not required, but if one is used, do not install the valve with the probe directly
in the flow of water. This may cause unwarranted discharge of the valve.
Toxic chemicals, such as those used for boiler treatment, shall not be introduced into the potable water.
• Flush water through the pipe to clean out metal powder, sand and dirt before connecting it.
• Take appropriate heat insulation measures (e.g., wrapping with heat insulation materials, using electric heaters)
according to the climate of the region to prevent the pipe from freezing.
• Use a union coupling or flexible pipe for connecting the pipes to reduce the force applied to the piping.
• Avoid using joints as much as possible to keep the piping simple.
• Avoid piping in which an air holdup can occur.
• Be sure to used approved piping materials.
Water piping
• When using plastic pipe, use pipe with an oxy-
gen diffusion barrier which is manufactured to
DIN4726.
• The longer the piping, the greater the heat loss.
Try to make the piping as short as possible.
The boiler ,when used in connection with a refrigeration system, must be installed so the chilled medium is piped in
parallel with the boiler with appropriate valves to prevent the the chilled medium from entering the boiler.
The boiler piping system of a hot water boiler connected to heating coils located in air handling units where they may
be exposed to refrigerated air circulation must be equipped with flow control valves or other automatic means to
prevent gravity circulation of the boiler water during the cooling cycle.
Installation and service must be performed by a qualified plumber. In the
Commonwealth of Massachusetts, this product must be installed by a licensed
plumber or gas fitter in accordance with the Massachusetts Plumbing and Fuel
Gas Code 248 CMR Sections 2.00 and 5.00. Observe all applicable codes.

System Sizing

• For optimal operation, design the piping and
size the pump to flow a minimum of 4.0 GPM.
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