26
• If tubing is to be run underground, it must be run
in a sealed watertight chase�
• Use care in routing tubing and do not kink or
twist� Use a good tubing bender on the vapor
line to prevent kinking�
• Route the tubing using temporary hangers; then
straighten the tubing and install permanent
hangers� Line must be adequately supported�
• If the vapor line comes in contact with inside
walls, ceiling, or flooring, the vibration of the
vapor line in the heating mode will result in noise
inside the structure�
• Blow out the liquid and vapor lines with dry
nitrogen before connecting to the outdoor unit
and indoor coil� Any debris in the line set will end
up plugging the expansion device�
Tubing Connections
Indoor coils have only a holding charge of
dry nitrogen� Keep all tube ends sealed until
connections are to be made�
• Use type “L” copper refrigeration tubing. Braze
the connections with the following alloys:
– copper to copper, 5% silver minimum
– copper to steel or brass, 15% silver minimum
• Be certain both refrigerant shutoff valves at the
outdoor unit are closed�
• Remove the caps and Schrader cores from the
pressure ports to protect seals from heat damage�
Both the Schrader valves and the service valves
have seals that may be damaged by excessive heat�
• Clean the inside of the fittings and outside of the
tubing with a clean, dry cloth before soldering�
Clean out debris, chips, dirt, etc�, that enters tubing
or service valve connections�
• Wrap valves with a wet rag or thermal barrier
compound before applying heat�
INSTALLATION
Interconnecting Tubing (cont�)
TEMPORARY
HANGER
PERMANENT
HANGER
ST-A1226-05-00
Tubing
