Daikin FHQ100BUV1B [47/340] Nitrogen

Field Piping and Wiring Si21-205A

36 Field Piping and Wiring

Not recommendable but in case of emergency

You must use a torque wrench but if you are obliged to install the unit without a torque wrench,

you may follow the installation method mentioned below.

After the work is finished, make sure to check that there is no gas leak.

When you keep on tightening the flare nut with a spanner, there is a point where the tightening

torque suddenly increases. From that position, further tighten the flare nut the angle shown

below:

Caution CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT PIPING

“

Do not use flux when brazing refrigerant piping. Therefore, use the phosphor copper brazing

filter metal (BCuP) which does not require flux.

”

(Flux has extremely harmful influence on refrigerant piping systems. For instance, if the chlorine

based flux is used, it will cause pipe corrosion or, in particular, if the flux contains fluorine, it will

damage the refrigerant oil.)

•

Before brazing local refrigerant piping, nitrogen gas shall be blown through the piping to

expel air from the piping.

If your brazing is done without nitrogen gas blowing, a large amount of oxide film develops

inside the piping, and could cause system malfunction.

•

When brazing the refrigerant piping, only begin brazing after having carried out nitrogen

substitution or while inserting nitrogen into the refrigerant piping. Once this is done, connect

the indoor unit with a flared or a flanged connection.

•

Nitrogen should be set to 0.02 MPa (0.2 kg/cm

) with a pressure-reducing valve if brazing

while inserting nitrogen into the piping. (Refer to Fig.15)

Pipe size Further tightening angle Recommended arm length of tool

φ6.4 (1/4") 60 to 90 degrees Approx. 150mm

φ9.5 (3/8") 60 to 90 degrees Approx. 200mm

φ12.7 (1/2") 30 to 60 degrees Approx. 250mm

Nitrogen

Pressure-reducing valve

hands valve

Taping

Refrigerant piping

Part to be

brazed

Nitrogen

Fig. 15