Multi F Outdoor Unit Engineering Manual
Table Of Contents
Brazing Practices
1. All joints are brazed in the field. Multi F refrigeration system components
contain very small capillary tubes, small orifices, electronic expansion valves,
oil separators, and heat exchangers that can easily become blocked.
•Store pipe stock in a dry place; keep stored pipe capped and clean.
•Blow clean all pipe sections with dry nitrogen before assembly.
2. Proper system operation depends on the installer using best practices and
utmost care while assembling the piping system.
•Use adapters to assemble different sizes of pipe.
•Do not use flux, soft solder, or anti-oxidant agents.
•Use a tubing cutter; do not use a saw to cut pipe. De-burr and clean all cuts before assembly.
3. 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 a
heat barrier spray product
Pressure-reducing
Valve
Packless
Valve
Tape
Nitrogen
Pipe to
be brazed
Refrigerant
Piping
Figure 78: Refrigerant Pipe Brazing.
Keep the piping system free of contaminants and debris such copper burrs, slag, or carbon dust during installation.
INSTALLATION & LAYOUT BEST PRACTICES
Refrigerant Piping System Layout
Flare Connection Practices
1. Place a couple of drops of refrigerant oil on the opening rim
of the flare before assembling. Take care not to add any
contaminants.
2. Align the center of the refrigerant pipe and corresponding
connection and tighten the flare nut by hand.
3. Following the guidelines as outlined in Table 185 for the amount
of torque to use, tighten the flare nut with a torque wrench until
the wrench clicks.
4. When flare is sufficiently tightened and the system has been
tested for refrigerant leaks, wrap insulation around the
connection.
Indoor Unit
Piping
Field-Supplied
Piping
Flare Nut
Improperly installed are connections can lead to refrigerant leaks.
Piping O.D. (in.) Torque (lbs. / ft.)
1/4 13-18
3/8 24.6-30.4
1/2 39.8-47.7
5/8 45.6-59.3
3/4 71.6-87.5
Indoor Unit Piping
Flare Nut
Field-Supplied
Piping
Figure 79: Flare Connection, Isometric View.
Figure 80: Flare Connection, Side View.
Wrench
Indoor Unit Piping
Open-End Wrench
Field-Supplied
Piping
Flare Nut
Table 185: Torque Wrench Tightening.
When tightening the are unit with a torque wrench, ensure the
direction for tightening follows the arrow on the wrench.
Figure 81: Using the Torque Wrench.
Due to our policy of continuous product innovation, some specications may change without notication.
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DESIGN & PRACTICES | 213
Refrigerant Piping Design and Best Practices
MULTI
F
MAX
MULTI
F