Calculation method of pipe fitting elbow geometric dimensions

　　ASME B16.9 ASME A234 WPB SMLS LR 90 Degree Pipe Fitting Elbow is a commonly used connecting pipe fitting in installation. It is used to connect pipe corners and change the direction of steel pipes.

　　Technical requirements for producing pipe fitting elbows:

　　Requires control of 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, leaving a certain angle and a certain edge. This requirement is also relatively strict, how thick the edge is, what the angle is, and the deviation range. There are regulations, and there are many more geometric dimensions than pipe fittings. The surface quality and mechanical properties of elbows are basically the same as those of pipes. In order to facilitate welding, the steel material of the pipe to be connected must be the same.

　　Geometric size calculation method

　►1.5 times pipe fitting elbow (also called conventional long radius pipe fitting elbow, 1.5D elbow): center height A = nominal diameter D*1.524, which is actually a multiple of diameter D*. The number after the decimal point of the result is rounded off. integer.

　　Example 1: The nominal diameter D of Φ219 is 200, the center height is 200*1.524=304.8, take 305

　　Example 2: If the diameter of Φ114 is 100, the center height is 100*1.524=152.4, take 152

　　(Algorithm suitable for elbow curvature radius of DN100 and above, convenient and quick calculation)

　►Poke height = center height A + radius of pipe fitting elbow

　　Example 1: Φ219 pipe fitting elbow, poke height=305+219/2=305+109.5=414.5

　　Example 2: Φ114 pipe fitting elbow, stamping height=152+114/2=209

　►The length of the outer arc = (center height + radius) * 3.14 * 2/360 * degrees, that is (height * 3.14 * 2 / 360 * degrees). From this, it can be calculated that the length of the outer arc of the 90 degree pipe fitting elbow = height * 3.14/2

　　Example 1: Φ219 pipe fitting elbow, outer arc length=414.5*3.14/2=650.8

　　Example 2: Φ114 pipe fitting elbow, outer arc length=209*3.14/2=328.1

　►Inner arc length = (center height-radius)*3.14*2/360*degrees=(center height-radius)*3.14/2

　　Example 1: Φ219 pipe fitting elbow, inner arc length = (305-219/2)*3.14/2=306.9

　　Example 2: Φ114 pipe fitting elbow, inner arc length = (152-114/2)*3.14/2=149.1

　►The cutting length of the pipe fitting elbow = pipe fitting elbow center height * 3.14/2 * pipe fitting elbow outer diameter / pipe diameter + (pipe wall thickness * 3) + processing allowance

　　Example 1: Φ219 pipe fitting elbow, blanking length =305*3.14/2*219/pipe diameter+pipe wall thickness*3+processing allowance

　　Example 2: Φ114 pipe fitting elbow, blanking length =152*3.14/2*114/pipe diameter+pipe wall thickness*3+processing allowance