ASME B31T:2018 pdf free download

ASME B31T:2018 pdf free download.Standard Toughness Requirements for Piping.
(b) the piping system is not subjected to unevaluated external loads such as maintenance loads, impact loads. and thermal shock
The curve used to generate columns 10 through 17 in lable 3.1.1 is provided in Mandatory Appendix II and may be used as an alternative to columns 10 through 17.
Column IR lists the minimum low-temperature service limit achievable by limiting stresses to less thaii 10% ol the tensile strength [I.e., the stress ratio (SR) s 0.3J and iniy be used without any additional Iow-teiupe.ature service requiremenis. At these stress levels, the design margin is considered adequate to prevent a brittle fracture failure mode. The low-temperature service limit listed in column IH may be used in lieu of that listed in column 4 when SR S 0.3.
3.6.2 Stress Ratio. The stress ratio is defined as the maximum of the following:
(a) nominal pressure stress (based on minimum pipe wall thickness less allowances) divided by the allowable stress at the design minimum temperature.
(b) for piping components with pressure ratings, the pressure for the condition under consideration divided by the pressure rating at the design minimum temperature.
(c) combined longitudinal stress due to pressure, dead weight, and displacement strain (stress intensifIcation factors are not included in this calculation) divided by the allowable stress at the design minimum temperature. In calculating longitudinal stress, the forces and moments in the piping system shall be calculated using nominal dimensions, and the stresses shall be calculated using section properties based on the nominal dimensions less corrosion, erosion, and mechanical allowances.
In determining the stress ratio, the loadings coincident with the metal temperature under consideration may be used in lieu of maximum design values. Where there arc several low-temperature design conditions, each shall be evaluated to determine the stress ratio.
3.7 Fabrication Requirements for Low- Temperature Service (Columns 7, 8, and 9 of TabLe 3.1-1)
3.7 1 Temperature timits, Column ?icts th” mtnrnum weki-permiled Lenipelatule. Vlieii a Lemperalure is listed, this is the design minimum temperature permitted for welded construction for this material group, thickness, and notes regardless of impact testing or any other requircments. Use of the material is prohibited at temperatures colder thaii this temperature unless permitted by column 9.