Duct Engineering - Carrier X-POWER Series Service Manual

Carrier service manual

5. Duct Engineering

5.1 Fabrication of Duct
1. The material, specification, performance and thickness of metal duct should be in accordance with the
relevant regulations of present National Products Standard. The thickness of steel sheet or galvanized
steel sheet should not be less than the regulation in table below:
Thickness of steel sheet duct (mm)
Diameter(D) or edge length (b) of duct
D(b)≤320
320＜D(b)≤450
450＜D(b)≤630
630＜D(b)≤1000
1000＜D(b)≤1250
2. The material, specification, performance and thickness of non-metal duct should be in compliance
with design and regulations of present National Products Standard.
3. The body, frame, fixing material and sealed cushion of fire-proof air duct should be made of
non-combustible materials. Its fire resistance rating should be in accordance with the design
requirement.
4. The sheathing of composite duct should be made of non-combustible materials. Inner insulation
material should be no burning or burning retardant with rating B1, and no harm to people's body.
5. The permitting deviation to outer diameter or long edge of duct: when no more than 300mm, it is 2mm;
when more than 300mm, it is 3mm. The permitting deviation of pipe end flatness is 2mm.
Discrepancy between two diagonal lines of rectangle duct shall not be more than 3mm. Discrepancy
between two diameters of any cross-cut circular flange shall not be more than 2mm.
5.2 Connection of Duct
1. Connection of metal duct
1) The seam of duct board splice should be stagger and cross-seam is not allowed.
2) Specification of metal duct flange shall not be less than the data as shown in table below.
Specification to flange and bolt of circular metal duct (mm)
Diameter of duct(D)
D≤140
140＜D≤280
280＜D≤630
630＜D≤1250
1250＜D≤2000
Specification to flange and bolt of rectangle metal duct (mm)
Dimension of long edge of duct(b)
b≤630
630＜b≤1500
1500＜b≤2500
2500＜b≤4000
3) Diameter of bolt and rivet to duct flange for middle/low pressure system should be no more than
150mm.
As for duct of high pressure system, it should be no more than 100mm.
4) Four angles of rectangle duct flange should be designed with screw hole.
Installation
Circular duct
Middle/low pressure system
0.5
0.6
0.75
0.75
1
Specification of flange
Flat steel
20×4
25×4
-
-
-
Specification of flange(angle steel)
25×3
30×3
40×4
50×5
R410a DC Inverter 60Hz
Rectangle duct
High pressure system
0.5
0.6
0.6
0.75
1
Specification of bolt
Angle steel
-
-
25×3
30×4
40×4
Specification of bolt
0.75
0.75
0.75
1
1
M6
M8
M6
M8
M10
141