Flange Bolt Pattern & P-T Reference - Local B16.5-Style Planning Rows
Look up bolt quantity, diameter, length, and torque for 150# through 2500# flanged connections
Source-aware planning tool for local ASME B16.5-style flange rows. Select pipe size (1/2" through 24") and pressure class (150, 300, 600, 900, or 1500) to screen bolt quantity, bolt diameter, bolt circle diameter, flange OD, bolt length, RF gasket reference dimensions, local torque band, Group 1.1 pressure-temperature rows, face notes, and cached RTJ ring rows. It is not a licensed current ASME table or assembly procedure; verify B16.5, PCC-1, B16.20/B16.21, manufacturer data, project specification, and qualified review before pressure-boundary use.
Calculate bolt torque for flange assembly
Torque-Tension Calculator →Look up pipe schedule and wall thickness
Pipe Schedule Reference →Review local relief-valve area prompts and source gaps
Relief Valve Sizing Calculator →Read the flange bolting guide
Flange Bolting Guide →How It Works
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Select Pipe Size
Choose a local NPS row from 1/2" through 24". Current ASME B16.5 tables, tolerances, markings, material limits, and manufacturer dimensions still govern real parts.
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Choose Pressure Class
Select Class 150, 300, 600, 900, or 1500. The class is not PSI; pressure-temperature rating still depends on material group, service temperature, weakest component, project code, and source review.
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Review Planning Details
Screen bolt count, bolt diameter, bolt circle diameter, flange OD, bolt length, RF gasket reference dimensions, and a local torque band for the selected row.
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Verify Before Assembly
Use current ASME B16.5, ASME PCC-1, ASME B16.20/B16.21, gasket and bolting manufacturer data, project specification, calibrated tools, and qualified review for actual assembly decisions.
Built For
- Pipefitters doing a first-pass flange bolt pattern screen before checking the current job specification
- Material coordinators building preliminary bolt kit notes before vendor and project review
- Piping engineers checking local planning rows against licensed ASME tables and project data
- Maintenance planners flagging RTJ, P-T, gasket, and bolting source checks before outage work
- Inspectors using the output as a source-review prompt, not as an acceptance record
- Procurement teams comparing local rows with manufacturer catalogs and approved material requirements
Features & Capabilities
Local B16.5-Style Rows
Covers local planning rows for NPS 1/2 through 24 in classes 150, 300, 600, 900, and 1500. Exact ASME table rows require current licensed source review.
Pressure-Temperature Screen
Shows harvested Material Group 1.1 P-T rows and psig conversions with a warning to verify the current ASME B16.5 table and material group.
Face and RTJ Source Gaps
Displays RF, FF, and RTJ reminders plus limited cached RTJ ring rows. ASME B16.20/B16.21 and gasket manufacturer data still govern gasket selection.
Torque Boundary Warnings
Shows local torque bands but keeps final bolt stress, gasket seating load, lubricant factor, tightening method, and inspection tied to ASME PCC-1 source review and manufacturer data.
Comparison
| Pipe Size | Class 150 Bolts | Class 300 Bolts | Class 600 Bolts | Class 900 Bolts | Class 1500 Bolts |
|---|---|---|---|---|---|
| 2" | 4 x 5/8" | 8 x 3/4" | 8 x 3/4" | 8 x 7/8" | 8 x 1" |
| 4" | 8 x 5/8" | 8 x 7/8" | 8 x 1" | 8 x 1-1/4" | 8 x 1-1/2" |
| 6" | 8 x 3/4" | 12 x 7/8" | 12 x 1" | 12 x 1-1/4" | 12 x 1-1/2" |
| 8" | 8 x 3/4" | 12 x 1" | 12 x 1-1/4" | 12 x 1-1/2" | 12 x 1-3/4" |
| 12" | 12 x 7/8" | 16 x 1-1/4" | 20 x 1-1/4" | 20 x 1-1/2" | 20 x 2" |
Assumptions
- Local rows are B16.5-style planning references for NPS 1/2 through 24 and classes 150 through 1500 only.
- Pressure-temperature rows are harvested Material Group 1.1 screening rows and must be checked against the current official table.
- Bolt material, gasket type, face type, thread engagement, and service conditions are not validated by the app.
- Actual flange assembly requires current source review, manufacturer data, project specification, jurisdictional code basis, and qualified review.
Limitations
- Does not reproduce complete current ASME B16.5 tables, tolerances, markings, materials, fittings, or all pressure classes.
- Does not cover B16.47 large-bore flanges, Class 2500, AWWA, API 6A, DIN/EN, or manufacturer special flanges.
- Does not calculate required bolt preload, gasket seating stress, or a project-controlled ASME PCC-1 assembly sequence.
- Cached RTJ ring rows are incomplete and require current ASME B16.20 plus gasket manufacturer validation.
- Does not validate damage, corrosion, cyclic service, hydrotest limits, thermal shock, pipe strain, field alignment, or jurisdictional acceptance.
References
- ASME B16.5-2025 - Pipe Flanges and Flanged Fittings source pointer.
- ASME PCC-1-2022 - Pressure Boundary Bolted Flange Joint Assembly source pointer.
- ASME B16.20-2023 - Metallic Gaskets for Pipe Flanges source pointer.
- ASME B16.21-2021 - Nonmetallic Flat Gaskets for Pipe Flanges source pointer.
Frequently Asked Questions
Learn More
ASTM Pipe Specs Explained
What A106, A53, A312, A333, A335, and A790 actually mean: seamless vs welded, high-temperature vs low-temperature service, and why A106 and A53 are not interchangeable.
Flange Bolting: B16.5-Style Patterns, Gaskets & Source Boundaries
Flange bolting concepts for B16.5-style joints, gasket and face selection, tightening sequence, PCC-1 review, and source-boundary warnings.
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