Mitsubishi Electric PURY-WP-YJM-A, Data Book

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3. Piping Design
4 - 33 SYSTEM DESIGN
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3-4. Water piping
3-4-1. Precautions for water piping
Consider the following when installing a water piping system.
1. Design pressure of the water piping
Use a water pipe that is strong enough to withstand the design pressure (1.0 MPa).
2. Water pipe type
Use of plastic pipe is recommended.
When using copper pipes, be sure to braze the pipes under a nitrogen purge. (Oxidation during may shorten the
life of the pump.)
3. Expansion tank
Install an expansion tank to accommodate expanded water.
4. Drain piping
Install the drain pipe with a downward inclination of between 1/100 and 1/200. To prevent drain water from freez-
ing in winter, install the drain pipe as steep an angle as practically possible and minimize the straight line. For
cold climate installation, take an appropriate measure (e.g., drain heater) to prevent the drain water from freezing.
5. Insulation
Cover the water pipe with insulating materials with the specified thickness or more to prevent thermal loss or con-
densation from collecting.
6. Air vent valve
Install air vent valves to the highest places where air can accumulate.
7. Maintenance valve
It is recommended to install valves on the inlet/outlet for each HBC controller branch for maintenance.
8. Water pressure gauge
Install a water pressure gauge to check the charged pressure.