Gree GUD35ZD/A-T Owner's Manual page 29

Pipe diameter (in.)
Screw on the flare nut of the flaring connecting pipe on the outdoor unit valve.
The method of screwing the flare nut is the same with that for indoor unit.
3.2.3.5 Thermal Insulation of Pipe Joint (Only for Indoor Unit)
Stick coupler heat insulation (large and small) to the place where connecting
pipes.
Reference A
Front outlet
Coupler heat
insulation (small)
on the pipe
3.2.3.6 Sealing of the Knock-off Hole
As for the built-in valve model, during the installation process for connection
pipe, when the connection pipe is passing through the knock-off hole, conduct
DC Inverter U-match Series Floor Ceiling Type Unit
1/4
3/8
1/2
5/8
3/4
7/8
Coupler heat insulation
(large) on the pipe
Liquid pipe
Gas pipe
Tightening torque
15-30
35-40
45-50
60-65
70-75
80-85
Reference A:
Cover this portion with heat
insulating material also without fail
No gap
25
(N· m)
Heat insulation pipe