Daikin ERQ Series Service Manual page 99

Piping connections
Make sure to install gas and liquid pipe diameters in function of the
air handling unit capacity class.
Air handling unit capacity class
50
63
80
100
125
140
200
250
Selection of piping material
1. Foreign materials inside pipes (including oils for fabrication)
must be 30 mg/10 m or less.
2. Use the following material specification for refrigerant piping:
Construction material: phosphoric acid deoxidized seamless
copper for refrigerant.
Temper grade: use piping with temper grade in function of the
pipe diameter as listed in the table below.
Pipe Ø
15.9
19.1
O = Annealed
1/2H = Half hard
The pipe thickness of the refrigerant piping should comply
with relevant local and national regulations. The minimal pipe
thickness for R410A piping must be in accordance with the
table below.
Pipe Ø Minimal thickness t (mm)
6.4
9.5
12.7
15.9
19.1
22.2
3. In case the required pipe sizes (inch sizes) are not available, it is
also allowed to use other diameters (mm sizes), taken the
following into account:
select the pipe size nearest to the required size.
use the suitable adapters for the change-over from inch to
mm pipes (field supply).
Installation and operation manual
90
Connection pipe
Gas pipe Liquid pipe
Ø12.7 Ø6.4
Ø15.9
Ø9.52
Ø19.1
Ø22.2
Temper grade of piping material
O
1/2H
0.80
0.80
0.80
0.99
0.80
0.80
Cautions for brazing
Be sure to carry out a nitrogen blow when brazing.
Brazing without carrying out nitrogen replacement or releasing
nitrogen into the piping will create large quantities of oxidized
film on the inside of the pipes, adversely affecting valves and
compressors in the refrigerating system and preventing normal
operation.
When brazing while inserting nitrogen into the piping, nitrogen
must be set to 0.02 MPa with a pressure-reducing valve (=just
enough so that it can be felt on the skin).
1 Refrigerant piping
2 Part to be brazed
3 Taping
4 Hands valve
5 Pressure-reducing valve
6 Nitrogen
For details, see manual of the outdoor unit.
Option kit for combination of Daikin condensing units
EKEQMCBV3
with field supplied air handling units
4PW52447-1