Tube wall thickness is expressed in terms of tube table number (Sch), weight table number (XS, XXS), wall thickness or calculated wall thickness, generally specific wall thicknesses need to be selected by the standard wall thickness series.
Wall thickness calculation
The pipe wall thickness of domestic materials can be calculated under GB/T 20801, GB 50316, SH/T 3059, and other standards; American Standard ASTM materials can be calculated under the wall thickness of ASME B31.1, ASME B31.3, and so on. If there are special instructions in the piping material grade, it can be calculated according to other standards. Wall thickness calculations shall be based on design pressure-temperature conditions and the minimum wall thickness required by corrosion or abrasion margins and machining additions. Wall thickness calculations shall be based on the most severe conditions when design pressure and design temperature are coupled.
Wall thickness series follow the standard
When the piping design selection of domestic materials, pipe size, and wall thickness can be implemented GB, HG, SH / T 3405 standards; when the pipe size and wall thickness are beyond the range of GB, HG, SH / T 3405 standards, it should be the implementation of specific engineering requirements.
In general, ≤ 1/2 "minimum wall thickness of steel pipe: carbon steel and low alloy steel pipe not less than Sch80; austenitic stainless steel pipe not less than Sch40S; galvanized steel pipe selection of the thickened type (for example, GB / T 3091).
Pipe wall thickness should not be less than the maximum of the following three items:
①. Wall thickness calculated following the provisions of Section 8.2 of SH/T 3059;
②. The wall thickness of the pipe is determined by d. / 150 (d. is the outer diameter of the pipe, mm);
③. The minimum selected wall thickness shall meet the requirements of the Table below:
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The minimum wall thickness for pipe and tube |
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Material |
Diameter |
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≤100 |
150~200 |
250~300 |
≥350 |
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Carbon and low alloy steels |
2.4 |
3.2 |
4.0 |
4.8 |
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High Alloy Steel and Stainless Steel |
1.5 |
2.3 |
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When American Standard ASTM materials are selected, for carbon steel and low alloy tubing, the outside diameter and wall thickness shall be following ASMEB36.10M. For austenitic stainless steel, tubes of nonferrous base materials, the outside diameter and wall thickness shall be following ASMEB36.19M, or ASMEB36.10M if the tube's outside diameter and wall thickness range exceeds ASME B36.19M. Where the range of pipe sizes and wall thicknesses exceed those specified in ASME B36.10M, the requirements specified for the specific project shall be implemented.
