DC Inverter U-match Series Cassette Type Unit 
25 
3.2.3.4 Connection Pipe of Indoor and Outdoor Units 
①.  Connect the pipe to the unit. Please follow the instructions stated in the figures 
below. Use both spanner and torque wrench. 
②.  When connecting the tapered screw nut, first apply chilled machine oil on its 
inner and outer surface and then screw it up for 3~4 circles. 
③.  Confirm the tightening torque by referring to the following table (If the screw 
nut is over-twisted, it may be damaged and cause leakage). 
④.  Check  whether gas  leakage occurs  to the  connection pipe  and then  apply 
thermal insulation, as shown below. 
⑤.  Wind sponge around the joint of gas pipe and heat insulation sheath of gas 
collecting pipe. 
⑥.  Be sure to connect gas pipe after liquid pipe is connected. 
Sponge
Threaded fastener(×4)
Liquid pipe
Gas inlet pipe
Heat insulation sheath
(for the gas tube)
Heat insulation sheath
(for the liquid tube)