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 with 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.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
