1. Incorrect inclination angle of pipeline and elbow angle

性能：折疊角不平直；矩形風管的兩個相對平面與兩端不平行；咬人不嚴格；對角線不相等。

Performance: The folding angle is not straight; The two opposite planes of a rectangular duct are not parallel to both ends; Not strict in biting people; Diagonal lines are not equal.

原因：管道成對平行，相對板的長度和寬度不相等；板材下料放樣設置的不正確。

Reason: The pipes are parallel in pairs, and the length and width of the relative plates are not equal; The setting of sheet cutting and layout is incorrect.

影響：會在通風管道上造成不均勻的力，安裝的管道不平直，法蘭墊圈不牢固，并且系統泄漏，從而導致空調負荷損失，導致使用壽命縮短。

Impact: It can cause uneven force on the ventilation duct, uneven installation of the duct, unstable flange gaskets, and system leakage, resulting in loss of air conditioning load and shortened service life.

措施：展開和下料時，應嚴格限制板材的直角，將板材的長度，寬度和檢查對角線控制在允許范圍內；落料后，管道相對部分的兩塊板應重疊以檢查尺寸精度。

Measures: When unfolding and cutting, the right angles of the board should be strictly restricted, and the length, width, and inspection diagonal of the board should be controlled within the allowable range; After blanking, the two plates in the opposite part of the pipeline should overlap to check the dimensional accuracy.

2、管道加工材料不符合標準

2. Pipeline processing materials do not meet the standards

性能：管道表面下沉，側面向外突出，變形明顯；板的表面不平整，厚度不均勻，有明顯的壓痕，裂紋，砂眼，疤痕和生銹。

Performance: The surface of the pipeline sinks, the side protrudes outward, and the deformation is obvious; The surface of the board is uneven, with uneven thickness, obvious indentations, cracks, sand holes, scars, and rust.

原因：該材料不合格，不能滿足制造風管的要求。

Reason: The material is not qualified and cannot meet the requirements for manufacturing air ducts.

影響：操作期間風管泄漏，空調負荷增加以及風管壽命和性能受到影響。

Impact: During operation, the air duct leaks, the air conditioning load increases, and the lifespan and performance of the air duct are affected.

措施：在制造管道之前，有必要檢查材料出廠合格證書，材料合格證書，外觀厚度等，以確保材料可用。

Measures: Before manufacturing pipelines, it is necessary to check the material factory certificate, material qualification certificate, appearance thickness, etc. to ensure that the materials are usable.