PSI to GPM Reference Index

Quality & Transparency Record

Calculation Errata & Mathematical Updates Log

In accordance with our Editorial Policy, this public errata log documents all formula verifications, standard updates, and mathematical corrections made to PSI to GPM calculation engines.

Transparency Commitment: We openly record technical revisions so engineers, contractors, and students can audit the mathematical integrity of our tools over time.

November 2026 Audit

Full System Trust, Sourcing & E-E-A-T Quality Audit

Scope: All 31 active tools, blog library, and legal frameworks.

  • Outbound Standards Citations Added: Directly hyperlinked primary consensus standards (NFPA 291, NFPA 13, NFPA 20, AWWA M31, ASTM D1785, Crane TP-410, and Hydraulic Institute) to official standards organizations.
  • Mathematical Fact-Check Verification: Re-verified fundamental derivations across hydraulic horsepower ($1714$ divisor), Freeman hydrant discharge ($29.83$ constant), Joukowsky water hammer impulse equation, and Hazen-Williams head loss constants.
  • Structured Data Integrity: Corrected Schema.org attribution types on editorial content from individual Person to collective Organization to ensure schema validity.
  • Catalog Count Synchronization: Updated homepage and human sitemap indices to accurately reflect all 31 active tools.
  • Privacy & Cookie Consent: Upgraded Google Analytics 4 tracking script to conditional execution upon explicit visitor consent, ensuring GDPR and ePrivacy alignment.
August 2026

Initial Platform Verification & Open Scoping Release

Scope: Launch of core fluid calculation engines.

  • Implemented 100% client-side computing guarantee across all calculators to ensure proprietary engineering parameters never transmit to remote servers.
  • Published explicit physical boundary limitations (steady-state liquid water at 60°F ambient) and life-safety Professional Engineer (PE) disclaimers.

How to Report an Errata or Discrepancy

If you suspect an error in any calculation, find a discrepancy with a revised standard edition, or spot a typographical error in our worked examples, please submit a report through our Contact page. Please provide the tool URL, input numbers tested, observed vs. expected outputs, and the governing engineering citation.