Flange Lookup

Flange Lookup is an offline reference for pipe flange dimensions, bolting, facings, flanged-fitting dimensions and pressure-temperature ratings for Classes 150 through 2500, NPS 1/2 through 24. It covers the usual ASME B16.5 range and clearly marks supplemental NPS 22 entries sourced under MSS SP-44.

Flange Lookup is part of the Weldbook AI family of apps from Appalachian Integrity LLC.

One purchase includes the complete app. No sign-in. No account. No ads. No in-app purchases. No subscription. Core reference content works offline after installation.

What's inside:
- Flange dimensions for Classes 150, 300, 400, 600, 900, 1500 and 2500 — outside diameter, thickness, hub dimensions, bolt-circle diameter, number and size of bolts, hole diameter, and stud or machine-bolt length, for welding-neck, slip-on, socket-weld, threaded, lap-joint and blind types.
- Facings — raised-face, flat-face and ring-joint groove dimensions, plus public-source finish references with an on-screen single-source warning.
- Flanged-fitting center-to-face dimensions for 90-degree and 45-degree elbows, tees, crosses, laterals, true Ys and reducers for all seven classes, 150 through 2500, each checked against two public sources; long-radius elbows for Classes 150 and 300. For Class 400 and up the numbers run to the flange edge with the 1/4-inch raised face not included, the way they are published, and the app says so on that tab.
- Public-source pressure-temperature ratings for supported material groups, in both psig/deg F and bar/deg C; an on-screen CURRENT-EDITION CHECK REQUIRED warning appears where sources may lag or use a related standard, and groups with no usable table remain materials-only.
- Bolting and material reference — bolt and nut specifications, material groups and gasket groups.
- Reference tools — a class finder for supported rating groups, bolt/stud dimension lookup, unit converter and thread note.
- Clear withheld-reference notices: this release does not publish dimensional tolerances, general flange shell-test guidance or a bolt-length calculation method; consult the governing standard and manufacturer.
- A "Where these numbers came from" screen naming every source, so you can see exactly how each table was checked.

Switch between inch and metric units any time. Your unit choice and your legal-acceptance record are the only things the app remembers, and both stay on your device.

Every value in this app is reference only. Confirm every dimension, rating and other value against the current edition of the standard you are actually working to before you use it for a design, purchase, fabrication or inspection decision. Standards get revised. The app identifies the standard family and public-source lineage associated with the data; it does not certify current-edition compliance or know which edition your job calls for.

This app is not affiliated with, endorsed by or licensed by ASME (the American Society of Mechanical Engineers), which publishes the standard. The standard is named only to describe what the data covers.

Flange Lookup collects no data. It makes no calls to us or to anyone else; the offline worker only reads the app's own files, and nothing you enter or view leaves your device. See the in-app Privacy Policy for the full explanation.

Built by Appalachian Integrity LLC, a Virginia inspection and engineering-documentation company, for inspectors, pipefitters, welders and engineers who need a flange number at the tailgate without pulling out a laptop.