1)  Completely  tighten  the  flare  nuts  of  the 
indoor and outdoor units, confirm that both 
the 2-way and 3-way valves are set to the 
closed position. 
2)  Connect the charge hose with the push pin 
of handle lo to the 3-way valves gas service 
port.. 
3)  Connect  the  charge  hose  of  handle  hi 
connection to the vacuum pump. 
4)  Fully  open  the  handle  Lo  of  the  manifold 
valve. 
5)  Operate the vacuum pump to evacuate.   
6)  Make evacuation for 30 minutes and check 
whether  the  compound  meter  indicates 
-0.1Mpa  (14.5Psi).  If  the  meter  does  not 
indicate -0.1Mpa (14.5Psi) after pumping 30 
minutes,  it  should  be  pumped  20  minutes 
more. If the pressure can’t achieve -0.1Mpa 
(14.5Psi) after pumping 50 minutes, please 
check  if  there  are  some  leakage  points. 
Fully  close  the  handle  Lo  valve  of  the 
manifold valve and stop the operation of the 
vacuum  pump.  Confirm  that  the  gauge 
needle  does  not  move  (approximately  5 
minutes after turning off the vacuum pump). 
7)  Turn the flare nut of the 3-way valves about 
45°  counterclockwise  for  6  or  7seconds 
after the gas coming out, then tighten the 
flare  nut  again.  Make  sure  the  pressure 
display  in  the  pressure indicator is  a  little 
higher than the atmosphere pressure. Then 
remove  the  charge  hose  from  the  3  way 
valve. 
8)  Fully  open  the  2  way  valve  and  3  way 
valve and securely tighten the cap of the 3 
way valve. 
 
2. Air purging by refrigerant 
 
Procedure: 
1).  Confirm  that  both  the  2-way  and  3-way 
valves are set to the closed position. 
2).  Connect  the  charge  set  and  a  charging 
cylinder to the service port of the 3-way valve.   
3). Air purging. 
Open the valves on the charging cylinder and 
the charge set. Purge the air by loosening the 
flare nut on the 2-way valve approximately 45’ 
for 3 seconds then closing it for 1 minute; repeat 
3 times. 
After  purging  the  air,  use  a  torque  wrench  to 
tighten the flare nut on the 2-way valve. 
4). Check the gas leakage. 
Check the flare connections for gas leakage. 
5). Discharge the refrigerant. 
Close  the  valve  on  the  charging  cylinder  and 
discharge the refrigerant by loosening the flare 
nut on the 2-way valve approximately 45’  until 
the  gauge  indicates  0.3Mpa  (43.5Psi)  to  0.5 
Mpa (72.5Psi). 
6). Disconnect the charge set and the charging 
cylinder, and set the 2-way and 3-way valves to 
the open position. 
Be sure to use a hexagonal wrench to operate 
the valve stems. 
7). Mount the valve stems nuts and the service 
port cap. 
Be sure to use a torque wrench to tighten the 
service port cap to a torque 18N·m. 
Be sure to check the gas leakage. 
 
12.4.4  Adding  the  refrigerant  after  running 
the system for many years 
 
Procedure