Kitano KC-Roka II-18M [50/64] Duct type air conditioners series roka ii

Duct type air conditioners

series: Roka II

7.3.2. Installation of refrigerant piping

Measure the necessary length of the connecting pipe, and make it by the following way.

1) Connect the indoor unit at  rst, then the outdoor unit.

2) Daub the surfaces of the  are pipe and the joint nuts with frozen oil, and wrench it for 3~4

rounds.

3) With hands before fasten the  are nuts. Be sure to use two wrenches simultaneously when

you connect or disconnect the pipes.

See the table 7.3.2. for tightening torque.

Table 7.3.2.

Pipe

gauge

Tightening

torque, N•m

Flare dimension A

Min (mm) Max

Flare shape

∅6.4

15~16 8.3 8.7

∅9.5

25~26 12.0 12.4

∅12.7

35~36 15.4 15.8

∅15.9

45~47 18.6 19.1

∅19.1

65~67 22.9 23.3

7.3.3. Vacuum dry and leakage checking

Use vacuum pump to change the moisture (liquid) into steam (gas) in the pipe and discharge

it out of the pipe to make the pipe dry. Under one atmospheric pressure, the boiling point of

water(steam temperature) is 100. Use vacuum pump to make the pressure in the pipe near

vacuum state, the boiling point of water falls relatively. When it falls under outdoor tempera-

ture, the moisture in the pipe will be vaporized.

Common vacuum dry procedure:

1) Vacuum dry (for the  rst time) — connect the all-purpose detector to the inlet of liquid pipe

and gas pipe, and run the vacuum pump more than two hours (the vacuum pump should be

below –755mmHg).

2) If the pump can’t achieve below –755mmHg after pumping 2 hours, moisture or leakage

point will still exist in the pipe. At this time, it should be pumped 1 hour more.

3) If the pump can’t achieve –755mmHg after pumping 3 hours, please check if there are some

leakage points.

4) Vacuum placement test: place 1 hour when it achieves –755mmHg, pass if the vacuum watch

shows no rising. If it rises, it shows theres moisture or leakage point.