Gree GUHD09NK3FO Service Manual page 73

U-Match Series DC
Inverter Service Manual
Be sure to connect the gas pipe after connecting the liquid pipe completely.
The tightening method is the same as that as at the indoor side.
For both indoor and outdoor unit side, check the joints for gas leaking by the use
of a gas leakage detector without fail when the pipes are connected.
Pipe Diameter Tightening Torque