Airwell KXV Series, Engineering Manual

Page: 221 / 380

Engineering manual
221
Insert nitrogen into the tubing, and set the pressure to 0.02MPa with the reducing valve.
B.
How to connect flare

See the following table for flare part machining dimensions.

When connecting the flare nuts, apply refrigerant oil to the inside and outside of the flares and turn them three or
four times at first. (Use ester oil or ether oil.)

Where arrowhead is pointed should coat with ether or ester oil.

When loosening a flare nut, always use two wrenches in combination. When connecting the piping, always use a
spanner and torque wrench in combination to tighten the flare nut.

See the following table for tightening torque.(Applying too much torque may cause the flares to creak.)
Outer dia.of copper
pipe(mm)/(Inch)
Torque(kg.cm) A(mm) Flare shape
φ 9.5(3/8”) 350~420 12.8~13.2
φ 15.9(5/8”) 750~800 19.3~19.7
φ 19.06(3/4”) 1000~1400
22.9~23.3

After all tubes have been connected, use nitrogen to perform a gas leak check.

When without torque wrench, please take following method as standard when tightening flare nut with wrench, stop
it and only rotate to angle stated as blow table when tightening torque increases quickly.
1 Refrigerant piping 4 Hands valve
2 Part to be brazed 5 Reducing valve
3 Taping 6 Nitrogen
Chart 1-21
Chart 1-22