Due to the relatively low yield strength of these materials, these higher stress values were established at temperatures where the short–
time tensile properties govern to permit the use of these alloys where slightly greater deformation is acceptable. The stress values in this
range exceed 662/3% but do not exceed 90% of the yield strength at temperature. Use of these stresses may result in dimensional changes
due to permanent strain. These stress values are not recommended for the flanges of gasketed joints or other applications where slight
amounts of distortion can cause leakage or malfunction. For Section III applications, Table Y–2 lists multiplying factors that, when applied
to the yield strength values shown in Table Y–1, will give allowable stress values that will result in lower levels of permanent strain.