What are the regulations regarding containers operating under \"low temperature and low stress conditions\"?

““A low-temperature and low-stress condition” refers to a condition in which the design temperature of the vessel or its pressure-bearing components is below -20°C, but its design stress – namely the maximum overall membrane and bending stress actually experienced by the vessel components under those design conditions – is less than or equal to one-sixth of the yield strength of the steel material at normal temperature, and not greater than 50 MPa. “The “low temperature and low stress condition” does not apply to low-temperature vessels whose standard minimum tensile strength of steel is greater than 540 MPa. “The “low temperature and low stress condition” is not applicable to bolt materials ； The selection of bolt material should take into account the difference between the design temperature of the bolt and that of the housing. When the container shell or its pressure-bearing components are used under \"low-temperature and low-stress conditions\", materials can be selected based on a temperature that is 50°C higher than the design temperature (40°C higher for containers that do not require post-weld heat treatment); however, this approach is not applicable to Q235 series steel plates. For carbon steel and low-alloy steel vessels, when the shell or its pressure-bearing components are used under \"low-temperature and low-stress conditions\", and if the design temperature plus 50°C (plus 40°C for vessels that do not require post-weld heat treatment) is not lower than -20°C, the provisions regarding low-temperature vessels need not be followed, unless otherwise specified.

“The “low temperature and low stress condition” does not apply to low-temperature vessels whose standard minimum tensile strength of steel is greater than 540 MPa. “The “low temperature and low stress condition” is not applicable to bolt materials ； The selection of bolt material should take into account the difference between the design temperature of the bolt and that of the housing. When the container shell or its pressure-bearing components are used under \"low-temperature and low-stress conditions\", materials can be selected based on a temperature that is 50°C higher than the design temperature (40°C higher for containers that do not require post-weld heat treatment); however, this approach is not applicable to Q235 series steel plates. For carbon steel and low-alloy steel vessels, when the shell or its pressure-bearing components are used under \"low-temperature and low-stress conditions\", and if the design temperature plus 50°C (plus 40°C for vessels that do not require post-weld heat treatment) is not lower than -20°C, the provisions regarding low-temperature vessels need not be followed, unless otherwise specified.

Is there such a thing as low temperature and low stress under external pressure conditions?