Engineering reference & educational aid. This tool is NOT a substitute for the ASME code, licensed engineering judgement, or a qualified review. Verify all results against the current ASME BPVC VIII-3 and Section II Part D.

Reference calculators and code guide

Turn the ASME BPVC VIII-3 (2025) high-pressure vessel code into practical, queryable engineering tools.

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Shell design by formula

Cylindrical & spherical monobloc shells under internal and external pressure (KD-221 / KD-222).

KD-221 · KD-222
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Hydrostatic test limits

Lower and upper bounds for the hydrostatic test pressure (KT-3).

KT-311 · KT-312
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Clause navigator & definitions

Browse the division's parts, scopes and key engineering terminology.

KG · KM · KD · KF …
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Unit & conversion tools

Pressure, stress, length, temperature, force and stress-intensity conversion.

SI ⇄ USC
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Design workflow guide

High-level route from materials through fabrication, testing and stamping.

KM → KD → KT
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Shell geometry (wall ratio)

Convert between wall ratio Y, diameters and wall thickness.

Y = Do/Di

What is covered

This division provides alternative rules for the design, fabrication, testing and documentation of high-pressure vessels (typically above 70 MPa / 10 000 psi) using design-by-analysis principles. The tools below implement a subset of the code's formula-based design rules as a study helper.

Cylinder — internal pressure

Design pressure or required thickness of a single-wall cylindrical shell under internal pressure (KD-221.1 / 221.2).

MPa
mm
mm
MPa
MPa
—
Closed-end uses ln(Y); open-end uses (Y^0.268−1) for Y ≤ 2.85.

Hemispherical shell — internal pressure

Design pressure or required thickness of a spherical monobloc shell under internal pressure (KD-221.5).

MPa
mm
mm
MPa
MPa
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Cylinder — external pressure

Maximum permissible external (collapse / buckling) pressure on a monobloc cylindrical shell, elastic form (KD-222.1).

mm
mm
MPa
MPa
—
P_D = E(Y−1)³ / [40(1−ν²)Y³]. Verify stability with elastic–plastic analysis.

Hydrostatic test pressure

Compute the permissible hydrostatic test pressure range at every point of the vessel (KT-311 / KT-312).

MPa
MPa
MPa
MPa
—
Open-end cylindrical shell uses (Y^0.268−1) when Y ≤ 2.85 and ln(Y) otherwise.

Shell geometry — wall ratio

Convert between wall ratio Y = D_o/D_i, diameters and wall thickness (KD-220).

mm
mm
mm
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Division structure & clauses

Search and browse the parts, articles and scopes of this division.

Key engineering terms

Terminology used in the design (KD) and analysis (Appendix 9) rules.

Design & construction workflow

High-level path through the mandatory parts of the division.

    Unit converter

    Convert between SI and US-Customary engineering units.

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