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INSTALLATION & LAYOUT BEST PRACTICES
Refrigerant Piping System Layout
Brazing Practices
It is imperative to keep the piping system free of contaminants and debris such as copper burrs, slag, or carbon dust during installation.
All joints are brazed in the field. Single Zone Cassette refrigeration system
components contain very small capillary tubes, small orifices, electronic expan-
sion 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.
• While brazing, use a dry nitrogen purge operating at a minimum pressure of three
(3) psig and maintain a steady flow.
• Blow clean all pipe sections with dry nitrogen prior to assembly.
•
Do not use a saw to cut pipe; use a tubing cutter. De-burr and clean all cuts
before assembly.
• Store pipe stock in a dry place. Keep pipe capped and clean.
• Use adapters to assemble different sizes of pipe.
•
Do not use flux, soft solder, or anti-oxidant agents.
• 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.
Flare Connection Practices
1. When connecting the flare nuts, coat the flare (outside only) with
polyvinyl ether (PVE) refrigeration oil only.
•
Do not use polyolyester (POE) or any other type of mineral
oil as a thread lubricant. These lubricants are not compatible with
PVE oil used in this system and create oil sludge leading to equip-
ment damage and system malfunction.
• Improperly installed flare connections can lead to refrigerant
leaks.
• When tightening the flare unit with a torque wrench, ensure the
direction for tightening follows the arrow on the wrench.
2. Initially hand tighten the flare nuts using three (3) or four (4)
turns.
3. To finish tightening the flare nuts, use both a torque wrench and a
backup wrench.
4. After all the piping has been connected and the caps have been
tightened, check for refrigerant leaks.
Loosening the Flare Nuts
Always use two (2) wrenches to loosen the flare nuts.
74 | INTRODUCTION
Due to our policy of continuous product innovation, some specifications may change without notification.
©
LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. "LG" is a registered trademark of LG Corp.
Figure 62: Refrigerant Pipe Brazing.
Refrigerant
Piping
Figure 63: Flare Connection, Isometric View.
Indoor Unit
Piping
Figure 64: Flare Connection, Side View.
Indoor Unit Piping
Flare Nut Field-Supplied
Table 48: Tightening Torque for Flare Nuts.
Pipe Size
Outside Diameter
(Inches O.D.)
1/4
3/8
1/2
5/8
3/4
Pressure-reducing
Pipe to
be brazed
Nitrogen
Packless
Tape
Valve
Field-Supplied
Piping
Flare Nut
Piping
Tightening Torque
(mm)
(ft-lbs)
6.35
13.0 ~ 18.0
9.52
24.6 ~ 30.4
12.7
39.8 ~ 47.7
15.88
45.6 ~ 59.3
19.05
71.6 ~ 87.5
Valve
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