Calculation method for flange bolt torque during hydrostatic testing
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How to calculate flange bolt torque during a hydrostatic test? GB150 specifies only the bolt pre-tension and the torque under operating conditions, but not those under pressure testing conditions. Thank you
In hydrostatic testing, the method for calculating the torque of flange bolts generally follows these steps: 1. Determine the material, specifications, and quantity of the flange bolts. 2. Calculate the magnitude of the preload based on the preload force and specifications of the flange bolts. 3. Calculate the loosening force based on the test pressure and the loosening coefficient of the flange bolts. The loosening coefficient can generally be referred to in relevant standards or empirical values. 4. Add the loosening force to the preload to obtain the actual torque. 5. Apply torque according to the installation method of the flange bolts (such as cross-tightening or symmetrical tightening). It should be noted that the above calculation methods are only for reference; the actual torque must be determined based on specific engineering requirements, the characteristics of the flange bolts, and the testing conditions. If you have specific engineering requirements, it is recommended to consult relevant professionals or conduct detailed calculations in accordance with relevant standards. .
Haven’t seen this requirement before; I’ll learn about it*
This post was last edited by wanlirn on 2023-7-8 08:25. This issue is somewhat complex; normal bolt design does not require verification of the stress levels during pressure tests. However, if it is stipulated in GB150.1----4.6.3, a specific analysis is necessary. . .
I haven’t calculated it; I refer to relevant standards when making a selection