Wall thickness calculation results
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I have a question: the pipe material is 20#, the operating temperature is 200 degrees, and the design pressure is 1.0 MPa. Using the wall thickness calculation formula specified in SH/T3059, I obtained a wall thickness of around 4.4 mm; after taking into account various factors such as C1 and C2, the minimum required wall thickness is 4.8 mm. However, according to the pipe grade table, the recommended wall thickness is around 10 mm. Why is there such a large difference? ? ?
I’m not familiar with calculations. In traditional pipe grade tables, pipes with a diameter of around 25 mm and a slightly higher pressure requirement have walls that are several millimeters thick. However, the data provided by pipe manufacturers regarding fittings shows that fittings with a wall thickness of 1 mm can withstand lower pressures compared to those with walls several millimeters thick as listed in those tables
For a pipe of such large diameter, a wall thickness of 10 mm is normal; the calculation of the wall thickness is intended solely for strength purposes, while choosing such a large thickness is mainly to take into account the impact on stiffness.
Is there any specific requirement in a certain standard for this?
Calculation needs to be combined with experience. What is the diameter of your pipe?
Firstly, the wall thickness of the pipe is part of a standard series; your calculated value represents the minimum requirement, and ultimately the standard wall thickness value shall be used. For a project, it’s not possible to consider each pressure factor individually in terms of the wall thickness; therefore, pressure levels need to be defined in order to simplify things, facilitate procurement and management, and improve versatility, so as to avoid errors during installation of the pipes. Regarding your specific question, it is indeed possible to make it thinner, provided that the additional loads applied are within acceptable limits – such as the self-weight, wind load, snow load, seismic acceleration, pipe span, and so on.
It’s too thin; the pipe spans will be very small, and many supports will be needed. It’s not easy to find pipes of such a large diameter that are also this thin