Daikin VRV FXAQ20ARVE6 Operation Manual

11Not recommendable but in case of emergencyYou must use a torque wrench but if you are obliged to install the unit without a torque wrench, you mayfollow 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 torquesuddenly increases. From that position, further tighten the flare nut the angle shown below:Table 2After the work is finished, make sure to check that there is no gas leak.CAUTIONCAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT PIPING“Do not use flux when brazing refrigerant piping. Therefore, use the phosphor copper brazing filler metal(BCuP-2: JIS Z 3264/B-Cu93P-710/795: ISO 3677) which does not require flux.”(Flux has extremely harmful influence on refrigerant piping systems. For instance, if the chlorine based flux isused, 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 thepiping.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 orwhile inserting nitrogen into the refrigerant piping. Once this is done, connect the indoor unit with a flaredor a flanged connection.• Nitrogen should be set to 0.02 MPa with a pressure-reducing valve if brazing while inserting nitrogen intothe piping. (Refer to Fig.14)CAUTIONBe sure to insulate any field piping all the way to the piping connection inside the unit. Any exposed pipingmay cause condensation or burns if touched.Pipe size Further tightening angle Recommended arm length of toolmm051.xorppAseerged09-06)”4/1(4.6mm002.xorppAseerged09-06)”8/3(5.9mm052.xorppAseerged06-03)”2/1(7.21mm003.xorppAseerged06-03)”8/5(9.51Refrigerant pipingPart to bebrazedTapingPressure-reducing valvehands valveNitrogen Fig. 14Nitrogen