Does this worksheet calculate pressure-vessel wall thickness to ASME or EN 13445?

No. It deliberately does not reproduce licensed code formulas. It only checks arithmetic between thickness values already established and documented by an approved code calculation.

What is documented calculation thickness?

It is the thickness value taken from the identified approved calculation at the stated component location and basis. Its exact definition is controlled by that calculation and governing code.

What belongs in additive allowance?

Only thickness that the controlled calculation explicitly instructs you to add arithmetically to the documented calculation thickness. Do not invent a generic corrosion or wear allowance.

What is minimum credited thickness?

It is the minimum thickness the approved calculation permits you to credit at the same location and basis after every applicable non-additive deduction or tolerance has been handled by the controlled process.

Does an above or equal comparison prove code compliance?

No. The relation is only arithmetic. Code applicability, inputs, formulas, load cases, materials, fabrication, examination, testing, jurisdiction and approval remain outside this worksheet.

Aritmetika řízená důkazy · nikoliv dimenzování podle norem

Porovnávač tlouštěk tlakových nádob s řízeným záznamem

Porovnejte tloušťku již stanovenou schváleným výpočtem podle licencované normy, včetně pouze explicitně povolených aditivních rezerv, s minimální uznatelnou tloušťkou na stejném zdokumentovaném základě.

Nejsou reprodukovány vzorce ASME/ENPřesná konverze mm ↔ inŽádné rozhodnutí o souladu

Jednotka tloušťky

Řídicí základ záznamu

Komponenta / místo výpočtu

Schválený výpočet / odkaz na dokument

Dokumentovaná výpočtová tloušťka t_výpočet (mm)

Povolená aditivní rezerva c_add (mm)

Minimální uznatelná tloušťka t_uznatelná (mm)

Potvrzuji, že t_výpočet, c_add a t_uznatelná pocházejí z identifikovaného schváleného výpočtu/procesu pro stejné umístění komponenty, vydání, geometrický základ a jednotky; c_add obsahuje pouze explicitně aditivní položky; t_uznatelná již řeší každou použitelnou neaditivní toleranci/odečtení podle požadavků tohoto procesu; a tuto aritmetickou relaci nebudu považovat za soulad s normou.

Aritmetické porovnání

Dokumentovaný aritmetický součet tcalc + cadd

Minimální uznatelná tloušťka

Aritmetický rozdíl tcredit − total

Aritmetický poměr tcredit / total

Nejedná se o přijetí podle normy: „nad“, „rovná se“ nebo „pod“ popisuje pouze zadaná čísla. Nevaliduje jejich definice, původní výpočet podle normy, výběr nominální tloušťky plechu, tolerance, zatěžovací případy, výrobu, zkoušení, testy nebo právní soulad.

Porovnání záznamů na stejném základě

t_{dokumentovaný,součet} = t_výpočet + c_add
rozdíl = t_uznatelná − t_{dokumentovaný,součet}
poměr = t_uznatelná / t_{dokumentovaný,součet}

Všechny tři vstupy tloušťky se musí vztahovat ke stejnému fyzickému umístění komponenty a kompatibilní definici tloušťky. Pracovní list interně převádí palce na milimetry přesně podle 1 in = 25,4 mm, provádí sčítání/odečítání/dělení a vrací vybranou zobrazovanou jednotku.

Pozitivní rozdíl znamená pouze, že zadaná uznatelná hodnota je číselně nad zadaným aritmetickým součtem; nula znamená rovnost; negativní rozdíl znamená pod. Nepoužívá se žádný bezpečnostní faktor, dovolené napětí, součinitel spoje, součinitel dna, vzorec tlaku ani pravidlo přijetí podle normy.

Nepodměňujte slepě nominální tloušťku plechu: t_uznatelná je minimální tloušťka, kterou vám schválený proces umožňuje uznat na místě a základě porovnání. Nominální tloušťka může vyžadovat toleranci v mm, ztenčení při tváření, ošetření koroze/eroze nebo jiná odečtení, která tato stránka nemůže odvodit.

The former page claimed minimum shell and head thicknesses to EN 13445 and ASME Section VIII from pressure, outside diameter, a fixed material value, a generic weld factor and corrosion allowance. That claim was not supportable.

Former component	Potvrzený problém
Design temperature	Collected but never used. Hard-coded allowable stresses therefore did not change with temperature.
Material presets	Fixed values were shown without a verified edition, product form, temperature row, notes or code-source traceability; ASME SA material labels were also offered under the EN route.
Joint / weld factors	Generic 1.0, 0.85 and 0.7 choices were applied to both code systems without verified joint category, examination scope or licensed rule.
Cylindrical formula	The displayed ASME inner-radius equation differed from the outside-diameter equation executed by JavaScript. The worked example used another radius approximation while the default route was EN.
Heads	Hemispherical and ellipsoidal equations were labelled code formulas while runtime comments called them approximations or simplifications. Flat-head coefficients 0.33 and 0.35 were hard-coded as “typical” without geometry/attachment scope.
Corrosion and plate recommendation	Universal service allowances and “use 12 mm plate minimum” ignored the controlled corrosion basis, negative tolerance, forming, other loads and code-specific requirements.

Changing one coefficient would conceal rather than fix these root causes. The unsupported formula engine, presets, automatic results and code-compliance language were removed.

This list is a scope reminder, not a substitute for either code. The responsible approved calculation must determine what applies, including:

jurisdiction, exact governing code/edition/addenda and component scope;
design, operating, test and external pressures; temperatures and coincident load cases;
component geometry, diameter/thickness convention, heads, openings, nozzles, supports and discontinuities;
material specification, product form, temperature-dependent allowable basis and degradation mechanisms;
joint category, weld details, examination extent, applicable coefficient and fabrication route;
corrosion/erosion allowance, design life, negative material tolerance, forming thinning and credited minimum thickness;
external-pressure stability, local loads, wind/seismic/dead weight, thermal effects, fatigue, creep, fracture and cyclic service as applicable;
reinforcement, inspection, nondestructive examination, pressure testing, overpressure protection, documentation and authorized approval.

Definitions control: whether an allowance is added to a calculated thickness, deducted from an available thickness, embedded elsewhere or handled by another rule cannot be decided by this page. Follow the licensed code and the approved project calculation exactly.

ASME BPVC Section VIII, Division 1

Oficiální ASME BPVC.VIII.1-2025 product page describes requirements for design, fabrication, inspection, testing and certification of vessels within its scope, with material/fabrication requirements and mandatory and nonmandatory appendices. This public scope confirms why a few generic equations cannot establish conformity; detailed rules require authorized access.

EN 13445-3

The official national-standards-body page for NBN EN 13445-3:2026 identifies it as active from 2 July 2026, replacing NBN EN 13445-3:2021+A1:2026. Its scope is design of unfired pressure vessels covered by EN 13445-1:2026 and constructed of steels under EN 13445-2:2026. Detailed rules remain licensed, and the applicable national adoption/jurisdiction must be confirmed.

Length conversion

NIST SP 811 Appendix B.8 lists 1 inch = 0.0254 metre and marks exact factors in bold. Therefore 1 in = 25.4 mm and the official unit check 0.5 in = 12.7 mm is exact.

Sources and lifecycle status accessed 13 July 2026. No ASME/EN clause number, table value or formula is asserted without the licensed text.

No. The former unsupported formula engine was removed. Enter only values already established by the identified approved licensed-code calculation.

Only items the controlled calculation explicitly requires to be added arithmetically at the same component location and thickness basis. Zero is valid. Do not insert generic corrosion values.

Only if the approved process explicitly permits that exact value to be credited after all applicable tolerance,forming and other deductions. This page cannot make that determination.

No. It is only the relation between three entered thickness records. The code calculation and every governing design,fabrication,inspection,test and approval requirement remain external.

Their correct values depend on exact code edition,material/product form,temperature,joint/examination scope and other licensed rules. Generic presets created false certainty.