Standard elbow – strength verification
Thread Content
In the design, after calculating the design wall thickness of the pipe and adding various allowances (such as 8 mm), and using elbows of the same thickness (8 mm) as specified in the standard (GB12459) for welding to that pipe, is it still necessary to verify the wall thickness of the elbows? Is there that standard as a basis?
There are thickness calculation formulas for elbows. . According to calculations, the thickness of the elbow should be greater than that of the pipe. . . Calculate 2 values: outer arc, inner arc. For these two values, the one on the outside is smaller than that of the straight tube, while the one on the inside is larger than that of the straight tube. . .
Standard SH/T3408 specifies that the design of standard fittings should be based on compressed seamless straight pipes made of the same material and with the same wall thickness. Standard GB12459 does not include such a requirement, but it provides a pressure testing formula for verifying the strength of fittings, namely P = 2ST/D, which is consistent with that used for steel pipes. Additionally, the wall thickness specified in GB12459 refers to the thickness at the ends; the wall thicknesses in other parts of elbows must be greater than this value, so there is no need to calculate the strength again.
For elbows, when placing an order you specify the nominal thickness. . As for the actual thickness of each part, it varies – some are thicker while others are thinner
The thickness at the diameter of the elbow is greater than that of the back arc; generally, the thickness of the elbow is 2 mm greater than that of the pipe. In manufacturing processes, the back arc portion of elbows experiences a significant amount of thinning. To meet safety standards, it is necessary to increase the thickness of the elbow. However, in the current domestic market, due to price factors, few manufacturers are willing to make it thicker. Hebei Xiangrui Pipe Industry Manufacturing Co., Ltd. specializes in the production of elbow pipe fittings; feel free to contact me if you have any questions. Hotline: 13803176995
It should no longer be necessary to calculate the thickness of the elbow; according to standard GB12459, the wall thickness referred to is that of the end portion, and the wall thicknesses of other parts of the elbow must all be greater than this value.