Daikin FHQ100BUV1B [56/340] Nitrogen

Daikin FHQ100BUV1B [56/340] Nitrogen
Si21-205A Field Piping and Wiring
Field Piping and Wiring 45
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 you 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
2
) with a pressure-reducing valve if brazing
while inserting nitrogen into the piping. (Refer to Fig. 12)
Make absolutely sure to execute heat insulation works on the pipe-connecting section after
checking gas leakage by thoroughly studying the following figure and using the attached
heat insulating materials for fitting (6) and (7). (Fasten both ends with the clamps (4).)
(Refer to Fig. 13)
Wrap the sealing pad (9) only around the insulation for the joints on the gas piping side.
(Refer to Fig. 13)
Caution
Be sure to insulate any field piping all the way to the piping connection inside the unit. Any
exposed piping may cause condensation or burns if touched.
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
φ15.9 (5/8) 30 to 60 degrees Approx. 300mm
φ19.1 (3/4) 20 to 35 degrees Approx. 450mm
Refrigerant piping
Part to be
brazed
Taping
Pressure-reducing valve
hands valve
Nitrogen
Nitrogen
Fig. 12

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