ASME B16.5 Flange Rating Lookup

For each operating point (pressure, temperature, material group), returns the minimum ASME B16.5 flange class that can safely contain the duty. Built-in pressure-temperature tables cover Group 1.1 (A105 carbon steel) and Group 2.3 (304 SS) across Classes 150, 300, 600, 900, 1500, and 2500.

CSV Input

Reference: ASME B16.5-2020 Pipe Flanges and Flanged Fittings: NPS ½ through NPS 24 Metric/Inch Standard, Tables 2-1.1. Only Groups 1.1 (A105 carbon steel) and 2.3 (304 stainless) are built in. For other groups (1.4, 1.7, 2.1, 2.2, 3.x), run the Python script locally and extend the data tables.

© 2026 Inflection Point Engineering, LLC. All rights reserved. The content of this page — including calculation methods, reference data, written analysis, interactive tools, and source code — is the intellectual property of Inflection Point Engineering, LLC and is protected under applicable copyright, trademark, and trade secret laws. Unauthorized reproduction, redistribution, modification, or derivative use in whole or in part is prohibited without prior written consent.

Disclaimer. This material is provided for informational and educational purposes only and does not constitute professional engineering advice. Calculations, reference data, and methodologies are based on published standards and accepted engineering practice but are not a substitute for engineering judgment, site-specific analysis, or review by a licensed Professional Engineer. Inflection Point Engineering, LLC makes no warranties, express or implied, regarding the accuracy, completeness, or fitness for a particular purpose of any content presented here, and shall not be liable for any direct, indirect, incidental, or consequential damages arising from its use. Users assume all risk associated with applying this content to real-world design, operations, or decisions.