【Daily Question】【Static Equipment AC Version...Question 141】August 9, 2019 Multiple-choice...Essay question
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bg4.png【Daily Question】【AC Version for Static Equipment...Question 141】 August 09, 2019 Multiple-choice questions...Essay questions...........................................................................Reward rules: 3 wealth for participation, 2 wealth for getting one question right; up to 10 wealth in total. No score will be given after two days, except during holidays. ...........................................................................1. Why is the safety factor for bolts relatively high? .............................................Answer: When determining the safety factor for bolts, the following factors should be taken into consideration: a) To ensure sealing, the initial stress applied when tightening the bolts should be greater than the design value ； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
a) To ensure sealing, the initial stress when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
a) To ensure sealing, the initial stress when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
a) To ensure sealing, the initial stress when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
a) To ensure sealing, the initial stress when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
Answer: The following factors should be considered when selecting the safety factor for bolts: a) To ensure sealing, the initial stress applied when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
a) To ensure sealing, the initial stress when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
It is difficult to control the machining accuracy and preload of bolts: Q
Answer: The following factors should be considered when selecting the safety factor for bolts: a) To ensure sealing, the initial stress applied when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ； d) Thermal stress caused by the temperature difference between the flange and the bolts, as well as by the different linear expansion coefficients of their materials. For the above reasons, the safety factor of the bolt is high.
1. During the process of tightening bolts, it is difficult to control the preload on these bolts, and it is likely that this preload will be higher than the value required by the design. 2. During operation, load cycling or fluctuations may cause the bolts to elongate, leading to loose connections and relaxed gaskets, requiring the bolts to be tightened many times. 3. Differences in the materials of the bolts and flanges, or differences in their temperatures, can cause additional thermal stress. 4. The bolt material used for sealing must not undergo plastic deformation; therefore, only the yield strength coefficient ns can be controlled.
This post was last edited by cxd11888 on 2019-8-8 08:00. a) To ensure sealing, the initial stress when tightening the bolts should be greater than the design value； b) During the pressure test, since the test pressure is higher than the operating pressure, the bolts may stretch and the gaskets may loosen; it is therefore necessary to tighten the bolts again ； c) After feeding materials into equipment with higher temperatures, the bolts need to be tightened again using heat ；