Elbow is a pipe fitting that changes the direction of the pipeline in the piping system. According to the angle, there are three commonly used ones: 45° and 90° and 180°. In addition, according to the needs of the project, it also includes other abnormal angle elbows such as 60°. The materials of elbows are cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, non-ferrous metals and plastics.

 

The diameter is 300MM, and the curvature is 90 degrees, so cutting: draw a straight line with a length of ∏ (d-td---outer diameter of the pipe, t---plate thickness)

Divide the line segment into 16 equal parts, from 0.1.2.3......16. Two equal-diameter right-angle elbow stakeout calculation formula: Yn=r cosα when 0°≤αn≤90° Yn=1/2(d-2t)cosα

When 90°<αn≤180°, Yn=1/2dcosα

In the formula, Yn---the equivalence point of the circle length of the expanded graph to the coordinate value of the curve;

r---Auxiliary circle radius;

d---outside diameter of the pipe;

t---plate thickness;

αn---Auxiliary circumference equal division angle; a pipe with a diameter of 300mm,

n optional 16α1=360°/16=22.5°α2=45°α3=67.5°α4=90°α5=112.5°α6=135°.α7=157.5°α8=180°

Calculation formula: Y0=1/2(d-2t)cos0°=0.5(d-2t)

Y1=1/2(d-2t)cos22.5°=0.4619(d-2t)

Y2=1/2(d-2t)cos45°=0.3536(d-2t)

Y3=1/2(d-2t)cos67.5°=0.1913(d-2t)

Y4=1/2(d-2t)cos90°=0

Y5=1/2 dcos112.5°=-0.1913d

Y6=1/2 dcos135°=-0.3536d

Y7=1/2 dcos157.5°=-0.4619d

Y8=1/2 dcos180°=-0.5d

Two curves appear, but connect these nine points, this is half, and the other half is the same, so the template is half of a 90-degree elbow.

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