### How to Calculation Geometric Size of Elbow

The **elbow** is a connection pipe fitting used to connect pipes and change the direction of the pipe in installation, so that the pipe can be turned at 90°, 45°, 180° and various degrees. Bending radius ≤ 1.5 times of pipe diameter is elbow, bending radius> 1.5 times of pipe diameter is bend.

Technical requirements for the produce elbows:

It is required to control the radius of curvature. For example, if the radius length is 1.5D, then the radius of curvature must be within the required tolerance range. Since most of these pipe fittings are used for welding, in order to improve the welding quality, the ends are beveled, with a certain angle and a certain side. This requirement is very strict. For the welding requirement, the steel material of the connected pipe should be the same.

1. 1.5 times the center height of the elbow A = diameter * 1.524, which is the diameter D * multiple, and the result will be the number after the decimal point is rounded to the nearest whole number. For example, the diameter D of 219 is 200, and the center height is 200*1.524=304.8, take 305; if the diameter of 114 is 100, the center height is 100*1.524=15.4, take 152. (The algorithm for the radius of curvature of elbows of DN100).

2. Poke height = center height + elbow radius, for example, the stamp height of an elbow with 1.5 times the diameter of 219 = 305 + 219/2=305+109.5=414.5

3. The length of the outer arc = (center height + radius) * 3.14 * 2/360 * degrees, that is (poke height) * 3.14 * 2/360 * degrees, from this, the length of the outer arc of the 90-degree elbow can be calculated=poke height*3.14/2

4. Inner arc length=(center height-radius)*3.14*2/360*degree

5. The blanking length of the elbow = the center height of the elbow * 3.14 / 2 * the outer diameter of the elbow / pipe diameter + (tube wall thickness * 3) + machining allowance, such as using a 180*8 pipe for blanking, push the system The 273 elbow can be calculated with the above formula, and the blanking length=381*1.57*273/180+24=931.22mm+ machining allowance.