Gree GMV-N140U/A-T Manual De Instalación Y Operación página 15

satisfy the clearance requirement of welding(the clearance requirement is 0.1~0.2mm normally).
4.2.3 Selection of Piping
(1) Ensure the inside of the pipes is clean and no foreign materials.
(2) Pipe specifications:
Pipe Φ（mm/inch）
4.2.4 Cautions for Welding
(1) Make sure there is nitrogen protection during welding.
Welding 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.
(2) When welding 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 welded
3) Taping
4) Hands valve
5) Pressure-reducing valve
6) Nitrogen
(3) For details, see manual of the outdoor unit.
Notes:
Copyright 2018. This translation is property of GREE PRODUCTS SL. All rights reserved. Total or partial reproduction without its express authorization is prohibited.
OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
Thickness(mm)
Φ6.35（1/4）
Φ9.52（3/8）
Φ12.70（1/2）
Φ15.9（5/8）
Φ19.05（3/4）
Φ22.2（7/8）
Φ25.40（1/1）
Φ28.6（9/8）
Φ31.8（5/4）
Φ34.90（11/8）
Φ38.10（12/8）
Φ41.30（13/8）
Φ44.5（7/4）
Φ51.4（7/4）
Φ54.1（17/8）
R410A System
Temper grade of piping material
≥0.8
≥0.8
≥0.8
≥1.0
≥1.0
≥1.2
≥1.2
≥1.2
≥1.3
≥1.3
≥1.5
≥1.5
≥1.5
≥1.5
≥1.5
Fig.4.2.4
12
O
O
O
O
O
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H