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About this app

Field Code is the field reference for inspectors who need a fast answer without digging through a code book. Type a question like "pitting api 510," "patch plates api 653," or "caustic tank," and get the requirement, the watch-outs to check, and the standard section to verify it against.

Field Code 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. No free trial. Everything works offline after installation, and the app requests no device permissions.

What's inside:
- 26 curated answer cards covering pitting, patch plates, weld spacing, service classes, injection points, deadlegs, CUI, caustic damage, chloride SCC, wet H2S, sulfidation, inspection intervals, and more.
- Standard tabs for API 510 (pressure vessel inspection), API 570 (piping inspection), API 653 (tank inspection, repair, alteration and reconstruction), and API 571 (damage mechanisms).
- A fast search box as the primary way to find an answer — type a plain question or a keyword and get a ranked list of matching cards.
- Load your own standard: drop in your own PDF, TXT, Markdown or HTML file. The text is extracted and searched on-device, with page-number snippets. The file name and source are never stored or displayed anywhere in the app.
- Works completely offline after install, with no network calls of any kind.

Every card names its source section and reminds you to verify against the current edition of the standard before you rely on it for an inspection, repair, or engineering decision. The answer cards are topic summaries prepared from public reference material — they are not quotations and not engineering advice.

Field Code is not affiliated with, endorsed by, or licensed by the American Petroleum Institute (API), which publishes the standards named in this app. The standards are named only to describe what the content covers.

Field Code collects no data. It makes no calls to us or to anyone else — everything runs and stays on your device, including any standard you load yourself. 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, and engineers who need a fast, sourced answer in the field.
API 510, 570, 653 & 571 field answers for inspectors. Works offline.
Updated on
Sep 17, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
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  • No data collected
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What’s new

First release. Offline field reference for API 510, API 570, API 653, and API 571, with 26 curated answer cards, a search box, and a "Load your own standard" feature for your own PDF/TXT/Markdown/HTML files. No account, no ads, no data collected.
Content rating
Everyone
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App support

About the developer
Appalachian Integrity LLC
john@appalachianintegrity.com
4917 Catawba Creek Rd Catawba, VA 24070-2103 United States
+1 270-832-2856

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