LG Art Cool Mirror Inverter Engineering Manual page 52

inStallation & layout bESt PraCtiCES
Refrigerant Piping System Layout
installation of refrigerant Piping / brazing Practices
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. DFS Single Zone Inverter 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. (See Figure 29.)
• 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.
• Use a tubing cutter, do not use a saw to cut pipe. 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
refrigerant Piping System insulation
All refrigerant piping, field-provided isolation ball valves, service valves, and elbows shall be completely insulated using closed cell pipe
insulation. The liquid and vapor lines must be insulated separately.
To prevent heat loss/heat gain through the refrigerant piping, all refrigerant piping including liquid lines, and vapor lines shall be insulated
separately. Insulation shall be a minimum 1/2" thick, and thickness needs to be increased based on ambient conditions and local codes.
All insulation joints are to be glued with no air gaps. Insulation material must fit snugly against the refrigeration pipe with no air space
between it and the pipe. Insulation passing through pipe hangers, inside conduit, and/or sleeves must not be compressed. Protect insulation
inside hangers and supports with a second layer. All pipe insulation exposed to the sun and outdoor elements shall be properly protected
with PVC, aluminum vapor barrier, or alternatively placed in a weather-resistant enclosure such as a pipe rack with a top cover; and meet
local codes.
The design engineer performs calculations to determine if the factory-supplied insulation jackets are sufficient to meet local codes and avoid
sweating. Add additional insulation if necessary. Mark all pipes at the point where the insulation jacket ends. Remove the jacket. Install
field provided insulation on the run-out and main trunk pipes first. Peel the adhesive glue protector slip from the insulation jacket and install
the clam-shell jacket over the fitting.
52 | reFrIGerAnT deSIGn
Due to our policy of continuous product innovation, some specifications may change without notification.
Figure 29: Refrigerant Pipe Brazing.
Refrigerant
Piping
Pipe to
be brazed
Nitrogen
Taping
Pressure-reducing
Valve
Valve