Introduction
a: L = 3m, the longitudinal seams more than one;
L = 5m longitudinal seams when more than 4;
L = 10m when more than two longitudinal seams
b: D = 300,400,500 mm, the circumferential seams more than two
D = 600,800,1000 circle seams when more than three
2Flange length：L1=150mm，L2=200mm
3.The bending deformation of the end ring is less than or equal to
1.2% of the original diameter, the end of the section to the duct
ring line is not perpendicular of not more than 4?.br /> a:Rings
at both ends at the end of lap 200mm onwards, the duct inner
circumferential seams and duct installation batten intersection
hanging, hanging hung between an inner one, the spacing is 2 times
Day
Distance (300mm) rings securely installed, seamless style.
b: L = 3 m or 5 m, the rings mounted reversing duct does not exceed
1/24th of the circumference of a circle 1, L = 10 m, the amount of
twist rings mounted to the circumference of the duct does not
exceed 1/16.
5.Ventilation Performance
a: air duct drag one thousand meters, kilometers, air leakage rate
in accordance with Table 3
table3
Duct diameter mm one hundred meters Drag N? S2/m8 one hundred
meters leakage rate%
300 ≤1728.0 ≤5.0
400 ≤410.0
500 ≤134.0
600 ≤54.0
800 ≤13.0
Note：L=10m，L=20m，L=30m，L=40m，L=50m
b: resistance to negative pressure in Table 4, the test does not
produce negative pressure resistant duct disjointed, coated cloth
tear, and the inner pressure of the separation, the joint opening
and other anomalies. Duct diameter shrinkage in accordance with
Table 4 provides:：
table4
Duct diameter mm pitch mm inner resistance to negative resistance
Pa duct diameter shrinkage%
300～500 150 ≥4500 5
600～800 100 ≥4000 3
7 coated cloth duct meet MT383-1995 standard.
