Does matching entered drilling prove that two flanges are interchangeable?

No. The comparison covers only the entered dimensions and hole count. Standard edition, pressure-temperature rating, material, flange type, facing, gasket, bolting, tolerances and the governing design still require verification.

Does this page convert PN to ASME Class?

No. PN and ASME Class are different designation systems whose ratings and dimensions depend on the controlling standard and complete flange basis. No automatic equivalence is asserted.

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.

No standards lookupNo gasket recommendationmm · inch

Geometric comparison

Entered numeric dimensions and hole count

PCD difference,B−A

Pitch-circle radial offset magnitude

Hole-count difference,B−A

Hole-diameter difference,B−A

수량	Record A	Record B	B−A

Equal-hole-circle geometry

angular pitch θ=360°/n
adjacent centre chord c=D·sin(π/n)
nominal adjacent ligament g=c−d_h

D is pitch-circle diameter,n is equally spaced hole count and d_h is hole diameter. Radial pitch-circle offset is |D_B−D_A|/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 It superseded the2007+A1:2013 edition.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.