One ideal beam span — not a support-spacing code check
Simply Supported Pipe-Section Beam Arithmetic
Invert one documented uniform-load deflection target for an ideal pin–roller hollow circular beam,and report the associated bending stress and reactions.No continuous-span coefficient or allowable spacing is invented.
gn=9.80665m/s² is conventional standard gravity.The span is the mathematical inversion of one ideal service-load deflection equation.It is not labelled allowable or maximum support spacing.The displayed stress is elastic bending stress from this uniform gravity load only and is not compared with a material/code allowable.
No continuous-span shortcut
A continuous multi-span pipe is not universally fixed–fixed.End spans,interior spans,unequal lengths,support settlement/stiffness and piping continuity change moments and deflections.The former `1/384` continuous coefficient and generic longer-span result are therefore not used.
Current code scope
ASME B31.1-2024 covers power-piping design through operation/maintenance;ASME B31.3-2024 covers process-piping materials/components,design,fabrication,assembly,erection,examination,inspection and testing.The public records do not establish universal2.5mm deflection or DN-based support-spacing tables.
Lähteet
Michigan State simply supported UDL moment/deflection example; University of Cincinnati Euler–Bernoulli scope; NIST conventional standard gravity; ASME B31.1-2024; ASME B31.3-2024.