通风管道工程量计算规则
Calculation rules for quantities of ventilation pipes
1, 薄钢板风管
1. Sheet steel air duct
（1）风管按不同规格以展开面积计算，管上检查孔、测定孔、送风口、吸风口等所占面积不扣除。
(1) The air duct is calculated based on the expanded area according to different specifications, and the area occupied by inspection hole, measuring hole, air supply outlet and air suction outlet on the duct is not deducted.
（2）计算风管长度时一律以图注中心线长度为准，包括弯头、三通、变径管、天圆地方等管件的长度，但不得包括通风部件（如风阀、风口等）所在位置的长度。风管直径和周长按图注尺寸展开。但咬口风管的接口及翻边量不得计算刷房 保定网站建设 保定强夯 卷扬式启闭机  保定网站制作 收费岛模具 遮阳网 麻绳在展开面积内。
(2) When calculating the length of the air duct, the length of the center line indicated in the drawing shall prevail, including the length of elbow, tee, reducer, round place and other pipe fittings, but shall not include the length of the location of ventilation components (such as air valve, air outlet, etc.). The diameter and perimeter of the air duct shall be expanded according to the dimensions indicated in the drawing. However, the joint and flanging amount of undercut air duct shall not be calculated in the developed area.