Supplied tolerance arithmetic
Coupling-Component Residual Unbalance
Convert a traceable permissible specific residual unbalance for the actual coupling component into total g·mm. Optional radius and speed inputs give an equivalent correction mass and rotating-force amplitude.
Residual-unbalance arithmetic
The first identity follows from 1 kg·μm=1 g·mm. The radius conversion and rotating-force equation are general mechanics, not acceptance formulas from ISO or API.
ISO 21940-11:2016 s Amd 1:2022 establishes rigid-rotor balancing procedures/tolerances, including required correction planes, allocation and balancing-process errors; flexible rotors are outside Part 11. The official public scope does not justify this page choosing a coupling G grade or dividing assembly mass by two.
The official API catalog identifies API Standard 671, 5th edition, as the current special-purpose coupling publication. Its numerical component-balance criteria are licensed content and are not reproduced or paraphrased here. Enter a verified requirement from the licensed standard, purchaser specification or manufacturer as e and identify its allocation basis.
No compliance claim: arithmetic agreement with a supplied e does not prove balance acceptance. Verify measurement uncertainty, tooling/mandrel and key conventions, component versus assembly state, correction-plane allocation and the current governing document.
