ASME B31.3 Edition 2022 Adopts ASME BPVC UG-44(b)Method

ASME B31.3 Edition 2022 (published in 2023) embraces ASME BPVC UG-44(b) for Piping External Loads: A Shift from Kellogg's Method?

In a recent update, the ASME B31.3 code has incorporated a reference to ASME BPVC Section VIII, Division 1, UG-44(b) as an approved method for qualifying piping external loads on ASME B16.5 and ASME B16.47 welding neck flanges. This addition marks an interesting development for piping engineers, as it introduces a comprehensive approach that considers both internal pressures and imposed external loads.

The UG-44(b) method outlined in ASME BPVC Section VIII, Division 1 specifies criteria for evaluating external loads (forces and bending moments) on flanged joints with welding neck flanges selected according to ASME B16.5, B16.47, and other applicable standards. The methodology involves ensuring that the vessel's maximum allowable working pressure (MAWP), corrected for static pressure on the flange at the design temperature, does not exceed the pressure-temperature rating of the flange.

One notable aspect of the update is the shift from the traditional Kellogg's Equivalent Pressure method, which has been widely used by piping engineers for assessing flange leakage. The UG-44(b) method, historically known as Case 2901, is highlighted as less conservative than the Kellogg method.

The ASME B31.3's decision to endorse the UG-44(b) method raises a relevant question: Does this signify a departure from the conventional use of Kellogg's method or other methods like "DNV" or "Koves" in piping engineering practices? Moreover, could it be seen as an attempt to establish a unified standard for flange leakage methods within the industry?