Documented dimensions required — no PN/Class conversion
Documented Flange Drilling Comparison
Compare two sourced drilling records geometrically. A dimensional match is not an interchangeability,pressure-rating or joint-suitability decision.
Geometric comparison
| Quantity | Record A | Record B | B−A |
|---|
Equal-hole-circle geometry
adjacent centre chord c=D·sin(π/n)
nominal adjacent ligament g=c−dh
D is pitch-circle diameter,n is equally spaced hole count and dh is hole diameter. Radial pitch-circle offset is |DB−DA|/2. These are elementary nominal-circle relations,not flange design formulas.
Standards context — no closed dimensions implemented
ASME B16.5—2025 is the current edition and covers pressure-temperature ratings,materials,dimensions,tolerances,marking and testing for its stated NPS/Class scope. Its official scope includes Class400,which the former page omitted.
EN1092-1:2018 is current and covers PN-designated steel flange types,facings,dimensions,tolerances,bolt sizes,materials and p/T ratings. It superseded the2007+A1:2013 edition. Neither document establishes a universal one-line PN↔Class conversion.
This page contains no standard dimensional row. Obtain both records from licensed current standards,approved drawings or verified manufacturer data. The inch is converted exactly as1in=25.4mm per NIST. Status/scope checked12July2026.
Not evaluated: DN/NPS equivalence,pressure-temperature capacity,material/product form,flange type,hub/bore,bolt specification,clearance/tolerance,angular clocking,facing finish/groove,gasket or ring number,joint assembly,external loads,corrosion,fatigue or jurisdiction.
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.
