ASME B31.1 / B31.3 / BPE Piping Calculators

Piping Toolset is a browser-based suite of piping, pressure-equipment, and support-structure calculators built for engineers who need report-grade output they can hand to a reviewer. Every calculator is a pure function: the same inputs always return the same result, and each one is locked behind a fixture-verified worked example that must reproduce a hand-checked reference case before a release ships.

ASME coverage spans the full B31 code family — B31.1 power, B31.3 process, B31.4 / B31.8 / B31.11 pipelines, B31.5 / B31.9 refrigeration and building services, and B31.12 hydrogen — plus BPE hygienic design, BPVC Section VIII pressure and App. 2 flange design, Section IX weld-metal A-Numbers, B31J-2023 SIFs and flexibility factors, B31E seismic, B31G remaining strength, B16.5 and B36.10 dimensional data, and the NM.1 / NM.2 non-metallic catalogs. Beyond ASME, the toolset covers API 520 / 521 relief sizing and scenario routing, API 610 / 560 / 620 / 650 / 660 / 661 and NEMA SM-23 nozzle loads, WRC-107 shell stresses, AISC and ACI support-structure compliance in LRFD or ASD — member, weld, base plate, anchors, pier, and soil in one load path — ASCE 7 wind and occasional-load combinations, EJMA expansion joint checks, and ISO 14692 for FRP/GRP.

Every calculation runs entirely in your browser: inputs are never transmitted to a server, so line numbers, design conditions, and process data stay on your device. Piping Toolset is operated by Flexible Piping Solutions LLC.

Open a toolset below, run a calculation, and add the result to a project report with a titleblock, a captured-calculation list, and print-to-PDF output. Worked examples, the fixture coverage ledger, and the calculation changelog document the same hand-checked cases the CI suite gates every release against, so every number in a report traces back to a citation.

Piping Calculators — code compliance · free

BPE / Hygienic — BPE fitting dimensions (DT-4.1), dead-leg L/d, GSD slope + drainability, spray-flow sizing, CIP velocity, tube-weld acceptance, PRE/PREN, WRC-1992 ferrite, Ra finish, EP/passivation
Process Piping — B31.3 — Wall thickness, allowable pressure, leak test, bends, miters, branch reinforcement
Power Piping — B31.1 — Wall thickness, allowable pressure, leak test, bends, branch reinforcement
Pipelines — B31.4 / B31.8 / B31.11 — Liquids, gas & slurry: wall thickness and allowable pressure (SMYS·F·E·T)
Building & HVAC — B31.5 / B31.9 — Refrigeration & building services: wall thickness, allowable pressure, leak test
Hydrogen Piping — B31.12 — Part IP with material performance factor Mf: pressure design, bends, miters, branches

Engineering Tools — free

General — Trapeze/strongback hanger sizing (channel + rod + max spacing), flange bolt-up sequence (star-pattern chart + pass torques), criticality evaluation (risk-matrix screening), Section IX weld-metal A-Numbers (Table QW-442), AISC 360 steel member check, EJMA expansion joint rating
Occasional Loads — Wind & Seismic — Wind on piping (ASCE 7), seismic design force (ASME B31E), and the ASCE occasional-load combination (governing w → M → Socc)
Pipe Supports — Spring variability & max spring rate, free thermal growth, pipe weight (lined/insulated), support spans
Thermal Flexibility — Expansion Loops — Expansion loop / leg sizing (guided cantilever): U-loops, Z-offsets, L-bends for metallic & plastic pipe, free thermal growth (in/100 ft), and thermal-expansion table interpolation (B31.3 Table C-1 / B31.1 App. B style)
Non-Metallic - FRP/HDPE/CPVC — PPI DR pressure rating, HDPE Code Case N-755, FRP/GRP (NM-2 / ISO 14692 / BS 7159), deflection-limited support spans, polymer thermal expansion (BPE PM-4.2.3), CPVC coming soon
Fatigue — Fatigue factor & equivalent cycles (B31.3 302.3.5(d)) and B31G / Modified B31G corroded-pipe remaining strength with ERF

Pro Tools

Report Manager — Titleblock, captured calculations, .pcp project files, batch runs, and comprehensive HTML / print-to-PDF reports
PiperSIF — SIF & Flexibility Factors — B31J-2023 / NM.1 — B31J-2023 Table 1-1 stress intensification & flexibility factors for metallic components, plus the NM.1-2022 Appendix IV HDPE i & k catalog
PiperPSV — Overpressure & Relief Sizing — API 520 / B31.1 App. II — API 520 orifice sizing (gas/steam/liquid), safety-valve discharge reaction force, API 521 scenario router

Pro Plus Tools

PiperHGR — PT&P Spring Sizing / 3D Model / Datasheet — PT&P variable & compact spring selection grid, hardware BOM with 3D assembly drawing, C-C rod solver, printable submittal sheet
PiperNOZ — API / NEMA / WRC — Nozzle Loading Tool — Nozzle load checks with NPS selector (API 610/560/660/661/650/620), API 610 Annex F pump qualification, NEMA SM-23 / API 617 combined index, Shell Nozzle Loads (WRC-107/VIII-2), UCS-66 MDMT / impact-exemption
PiperFLG — Bolted Flange Analysis — Peq & ASME Sec. VIII App. 2 — Kellogg equivalent-pressure (Pe) screen and ASME Sec VIII Appendix 2 flange design, auto-filled from B16.5 with a parametric 3D model; P-T rating from the 2025 (current) or 2017 (retired) edition tables

Ultimate Tools

PiperFEA — Nozzle/Shell Finite Element Analysis — Design-grade FEA of nozzle-to-shell junctions: gmsh shell meshing + CalculiX solve, pressure and external nozzle loads, stress linearization vs. allowables
PiperISO — 3D Piping Isometric Drawing Tool — Draw fabrication isometrics on a 3D routing model (ASME B16.9/B16.5/B16.10 dims, Class 150–900): auto-dimensioning, weld symbols, live 3D view, BOM & cut list
PiperSTR — AISC & ACI Compliance (LRFD/ASD) — Whole pipe-support load path in one run: member, weld, base plate, anchors, pier & soil

Project Utilities

Utilities — Unit conversion, pipe section properties (B36.10 sizes & schedules), batch import/export, CSV ⇄ JSON, interpolation

Every calculator, documented with method, limitations, and a fixture-verified worked example →