[Daily question] [Static Equipment Exchange Edition...Question 163] Multiple choice question on June 12, 2019...Q&A

“"Low temperature and low stress working condition" refers to the working condition when the design temperature of the vessel or its pressure components is lower than or -20°C, but its design stress (the maximum primary overall film and bending stress actually endured by the vessel components under this design condition) is less than or equal to one-sixth of the standard normal temperature yield strength of steel and not greater than 50MPa. Except for special requirements, it does not need to be considered as a low-temperature pressure vessel.

“"Low temperature and low stress working condition" refers to the working condition when the design temperature of the vessel or its pressure components is lower than or -20°C, but its design stress (the maximum primary overall film and bending stress actually endured by the vessel components under this design condition) is less than or equal to one-sixth of the standard normal temperature yield strength of steel and not greater than 50MPa. “"Low temperature and low stress working condition" is not applicable to cryogenic vessels with the lower limit of the standard tensile strength of steel greater than 540MPa.

Low-temperature and low-stress working conditions refer to working conditions in which the design temperature of the container or pressure component is lower than or equal to -20°C, but the tensile film stress is less than or equal to one-sixth of the standard normal temperature yield point of steel and not greater than 50Mpa. Should vessels under low-temperature and low-stress conditions be considered as low-temperature pressure vessels? In this working condition, if the design temperature plus 50°C is higher than -20°C, there is no need to follow the regulations for low-temperature pressure vessels.

“"Low temperature and low stress working condition" refers to the working condition when the design temperature of the vessel or its pressure components is lower than or -20°C, but its design stress (the maximum primary overall film and bending stress actually endured by the vessel components under this design condition) is less than or equal to one-sixth of the standard normal temperature yield strength of steel and not greater than 50MPa. No need

Low-temperature and low-stress working conditions refer to working conditions in which the design temperature of the container or pressure component is lower than or equal to -20°C, but the tensile film stress is less than or equal to one-sixth of the standard normal temperature yield point of steel and not greater than 50MPa. When a vessel or pressure component is used under "low temperature and low stress conditions", if its design temperature is higher than -20°C after adding 50°C, it is not necessary to follow the regulations for low temperature pressure vessels.

Low-temperature and low-stress working conditions refer to working conditions in which the design temperature of the container or pressure component is lower than or equal to -20°C, but the tensile film stress is less than or equal to one-sixth of the standard normal temperature yield point of steel and not greater than 50Mpa. Should vessels under low-temperature and low-stress conditions be considered as low-temperature pressure vessels? In this working condition, if the design temperature plus 50°C is higher than -20°C, there is no need to follow the regulations for low-temperature pressure vessels.

1. "Low-temperature and low-stress working conditions" refers to the working conditions when the design temperature of the vessel or its pressure components is lower than or -20°C, but its design stress (the maximum primary overall film and bending stress actually endured by the vessel components under this design condition) is less than or equal to one-sixth of the standard normal temperature yield strength of steel and not greater than 50MPa. 2. "Low-temperature and low-stress working conditions" are not necessarily applicable to cryogenic vessels whose lower limit of the standard tensile strength of steel is greater than 540MPa. “"Low temperature and low stress conditions" are not applicable to bolt materials ； The choice of bolt material should take into account the difference between the bolt and housing design temperatures. When the vessel shell or its pressure components are used under "low temperature and low stress conditions", the material can be selected according to the temperature after the design temperature is increased by 50°C (for vessels that do not require post-weld heat treatment, add 40°C), but it is not applicable to Q235 series steel plates. For carbon steel and low alloy steel vessels, when the shell or its pressure components are used under "low temperature and low stress conditions", if the design temperature plus 50℃ (for vessels that do not require post-weld heat treatment, add 40℃) is not lower than -20℃, unless otherwise specified, there is no need to follow the regulations on cryogenic vessels.

This post was last edited by wwwguo on 2019-6-14 10:28: It refers to the working condition when the design temperature of the container or its pressure components is lower than -20°C, but the tensile film stress is less than or equal to one-sixth of the standard normal temperature yield point of steel and not greater than 50Mpa. When the vessel or its pressure components are used under "low temperature and low stress conditions", if the design temperature plus 50°C is higher than -20°C, there is no need to comply with the regulations for low-temperature pressure vessels.

Low-temperature and low-stress working conditions refer to the working conditions when the design temperature of the shell or its pressure components is lower than -20°C, but the design stress (the maximum primary overall film and bending stress actually endured by the container components under this design condition) is less than or equal to 1/6 of the standard normal temperature yield strength of the steel, and not greater than 50MPa. For carbon steel and low alloy steel vessels, when the shell or its pressure components are used under "low temperature and low stress conditions", if the design temperature is not lower than -20°C after adding 50°C (for vessels that do not require post-weld heat treatment, add 40°C), there is no need to follow the regulations on low-temperature vessels unless otherwise specified.

Low-temperature and low-stress working conditions refer to working conditions in which the design temperature of the container or pressure component is lower than or equal to -20°C, but the tensile film stress is less than or equal to one-sixth of the standard normal temperature yield point of steel and not greater than 50Mpa. Should vessels under low-temperature and low-stress conditions be considered as low-temperature pressure vessels? In this working condition, if the design temperature plus 50°C is higher than -20°C, there is no need to follow the regulations for low-temperature pressure vessels.