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General Refrigerant Piping System Information
Due to our policy of continuous product innovation, some specifications may change without notification.
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GENERAL REFRIGERANT PIPING SYSTEM
1. All joints are brazed in the field. Multi V refrigeration system components contain very small capillary tubes, small orifices, electronic
expansion valves, oil separators, and heat exchangers that can easily become blocked. Proper system operation depends on the installer
using best practices and utmost care while assembling the piping system.
2. Store pipe stock in a dry place; keep stored pipe capped and clean.
3. Blow clean all pipe sections with dry nitrogen prior to assembly.
4. Use adapters to assemble different sizes of pipe.
Do not braze in an enclosed location.
Do not allow the refrigerant to leak during brazing. Always test for gas leaks
before and after brazing.
If the refrigerant combusts, it generates a toxic gas the will cause physical injury or death.
• Braze the pipes to the service valve pipe stub of the outdoor unit.
• Before brazing the refrigerant piping, perform a nitrogen replacement procedure or charge nitrogen into the refrigerant piping during brazing,
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WARNING
Figure 9: Refrigerant Pipe Brazing.
Pressure-reducing
Valve
Valve
Taping
Nitrogen
Pipe to
be brazed
Refrigerant
Piping
Brazing Procedure
5. Always use a non-oxidizing material for brazing.
Do not use flux, soft solder, or
anti-oxidant agents. If the proper material is not used, oxidized film will accumulate
and clog or damage the compressors. Flux can harm the copper piping or refriger-
ant oil.
6. Use a tubing cutter,
do not use a saw to cut pipe. De-bur and clean all cuts
before assembly.
7. Brazing joints:
• Use a dry nitrogen purge operating at a minimum pressure of three (3) psig and
maintain a steady flow.
• Use a 15% silver phosphorous copper brazing alloy to avoid overheating and
produce good flow.
• Protect isolation valves, electronic expansion valves, and other heat-sensitive
control components from excessive heat with a wet rag or heat barrier spray.
Figure 10: Split Compact DOAS Piping Connections.
Table 8: Split Compact DOAS Piping Sizes (O.D., Inch).
Piping Type
ARND153DCR4 ARND203DCR4
Liquid 1/2
1/2
Low Pressure
1-1/8
1-1/8
High Pressure
3/4
7/8
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Brazing Procedure
