Issues with pressure vessel studs (bolts)
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1. TSG 21-2016 Code for Safety Inspection of Fixed Pressure Vessels 3.2.5 Pipe flanges for pressure vessels: (1) The design of steel pressure vessel pipe flanges, gaskets, and fasteners shall comply with the provisions of the HG/T20592~HG/T20635-2009 series of standards； (2) For pressure vessels containing liquefied petroleum gas, media with extremely high or high toxicity, as well as media with strong permeability and toxic effects, the pipe flanges shall comply with the provisions of the HG/T20592–HG/T20635-2009 series of standards,... 2. 7.1.1 in GB/T150.3-2011...... When the JB/T4700–4707 standards are adopted, the calculations specified in this chapter may be omitted. Question 1: For pressure vessels designed in accordance with GB/T150, can flanges and fasteners from the HG/T20592~HG/T20635-2009 standard series be used directly, without needing to consider clause 7.1.1 of GB/T150.3-2011, which states that \"when the JB/T4700~4707 standards are used, the calculations specified in this chapter can be omitted.\" ”This sentence? Question 2: Can materials for studs that are not listed in GB/T150.2-2011 be used those specified in HG/T20592~HG/T20635-2009? If it is possible to use such a material, how can the requirements regarding the V-notched Charpy impact test for stud materials as specified in Chapter 7 of GB/T150.2-2011 be met? Question 3: Screw studs specified in HG/T20592~HG/T20635-2009 can be used, but can materials listed in GB/T150.2-2011 but not in HG/T20592~HG/T20635-2009 be used as well? Question 4: When using studs specified in HG/T20592~HG/T20635-2009, and whose material is one of those listed in GB/T150.2-2011, does the material of these studs need to meet the requirements of Chapter 7 of GB/T150.2-2011?
1. The HG/T20592~HG/T20635-2009 series of standards can be used directly; these are **industry standards**. The JB/T4700~4707 standards are equipment flange standards. Used on equipment flanges. 2. It cannot be used. This is because the materials specified in the HG/T20592~HG/T20635-2009 series of standards have been approved through calculations. If you need to replace the standard material with a non-standard flange, then the fasteners must be designed for non-standard flanges. 3. The material standards for fasteners specified in the flange standard cannot be changed arbitrarily; if such standards are not available in the flange standard, calculations must be carried out. 4. Chapter 7 of GB/T150.2-2011 specifies explicitly that when the JB/T4700~4707 standards are adopted, the calculations specified in this chapter can be omitted. In the design, we try to use materials specified by standards in order to avoid unnecessary calculations. The above opinions are for reference only.
Answer: Question 1: Select the appropriate fasteners according to the corresponding standards; no calculation is required. Do not use fasteners of different forms from those specified by the standards in conjunction with the flanges. Question 2: Materials that are not listed cannot be selected. Question 3: It also cannot be selected directly; calculation is required. Question 4: The material properties must also meet the requirements specified in Article 7 of GB/T150.2; this requirement should be included when placing orders.
The flange calculations in the industry standards differ from those for 150; using the Walters method for 150 is likely to result in failure. The Whartons method is a very conservative calculation approach; if it fails, it simply cannot be used, which is why this rule was established.
What calculation method is used for flange calculations in HG industry standards?
HG/T is formulated with reference to the ISO7005 and ASME B16.5 standards. So the calculations are also carried out in accordance with European standards or relevant specifications.