Engineering reference worksheet
DN / NPS / OD Cross-Reference
Look up a publicly corroborated DN–NPS pairing and pipe outside diameter. DN, NPS and measured diameter are kept separate.
Výsledky
| DN | NPS | Source OD (in) | Public table OD (mm) | Exact OD × 25.4 (mm) |
|---|
What ISO 6708 does—and does not—define
ISO 6708:1995 defines DN as an alphanumeric designation for reference purposes. It consists of the letters DN followed by a dimensionless whole number indirectly related to physical size. The standard supplies a preferred DN series; it does not itself define NPS, outside diameter, inside diameter or wall thickness.
What this worksheet reports
Each row contains four distinct data items: a DN designation, an NPS designation, a source outside diameter in inches, and a publicly displayed metric OD. The calculated value uses only the exact unit identity:
Because published tables round metric displays, the public metric value can differ slightly from the exact conversion. For example, 10.750 in × 25.4 = 273.05 mm, while the public table display is commonly 273.0 mm.
Corrected size: NPS 5 has a source OD of 5.563 in and public metric OD of 141.3 mm. A separate 5.500 in / DN125 product size also appears in current manufacturer literature; it must not be substituted for NPS 5.
Scope and limitations
This is an exact-match cross-reference, not a dimensional design calculator. It does not infer a nearest size and does not provide schedule, wall thickness, inside diameter, tolerance, mass, pressure rating, material compatibility or fitness for service. Those require the applicable product/material standard and project specification.
Source limitation: ISO 6708:1995 is verified for the meaning and preferred series of DN. The DN/NPS/OD rows are corroborated against current publicly available manufacturer tables. Direct row-by-row verification against licensed ASME B36.10-2022 Table 2-1 and separate applicability checks for ASME B36.19-2022 remain NEEDS_LICENSED_SOURCE.
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