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.

Evidence-controlled arithmetic · not code sizing

受控壓力容器壁厚記錄比較器

Compare a thickness already established by an approved licensed-code calculation, plus only its explicitly authorized additive allowances, with a minimum credited thickness on the same documented basis.

No ASME/EN formulas reproducedExact mm ↔ in routeNo compliance verdict

Thickness unit

Governing record basis

Component / calculation location

Approved calculation / document reference

Documented calculation thickness t_calc (mm)

Authorized additive allowance c_add (mm)

Minimum credited thickness t_credit (mm)

I confirm that t_calc, c_add and t_credit come from the identified approved calculation/process for the same component location, edition, geometry basis and units; c_add contains only explicitly additive items; t_credit already handles every applicable non-additive tolerance/deduction as required by that process; and I will not treat this arithmetic relation as code compliance.

算術比較

—

Documented arithmetic total tcalc + cadd

—

Minimum credited thickness

—

Arithmetic margin tcredit − total

—

Arithmetic ratio tcredit / total

—

Not code acceptance: “above”, “equal” or “below” describes only the entered numbers. It does not validate their definitions, the original code calculation, nominal plate selection, tolerances, load cases, fabrication, examination, test or legal conformity.

Same-basis record comparison

t_{documented,total} = t_calc + c_add
margin = t_credit − t_{documented,total}
ratio = t_credit / t_{documented,total}

All three thickness inputs must refer to the same physical component location and compatible thickness definition. The worksheet converts inches to millimetres internally with exactly 1 in = 25.4 mm, performs addition/subtraction/division, and returns the selected display unit.

A positive margin means only that the entered credited value is numerically above the entered arithmetic total; zero means equal; a negative margin means below. No safety factor, allowable stress, joint coefficient, head coefficient, pressure formula or code acceptance rule is applied.

Do not substitute nominal plate thickness blindly: t_credit is the minimum thickness the approved process permits you to credit at the comparison location and basis. Nominal thickness may require mill tolerance, forming thinning, corrosion/erosion treatment or other deductions that this page cannot infer.

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	Confirmed problem
設計溫度	已收集但從未使用。因此，硬編碼的允許應力不會隨溫度變化。
材料預設值	顯示的固定數值缺乏經核證的版本、產品形式、溫度行、備註或規範來源追溯性；ASME SA 材料標籤也出現在 EN 路徑下。
接頭/焊接係數	通用的 1.0、0.85 和 0.7 選項被應用於兩個規範系統，且未經核證的接頭類別、檢查範圍或授權規則。
圓柱殼公式	顯示的 ASME 內半徑方程式與 JavaScript 執行的外徑方程式不同。演算範例使用了另一種半徑近似值，而預設路徑為 EN。
封頭	半球形和橢圓形方程式被標記為規範公式，而執行時註釋稱其為近似值或簡化值。平封頭係數 0.33 和 0.35 被硬編碼為「典型」值，且無幾何形狀/連接範圍。
腐蝕與板材建議	通用的使用裕度和「至少使用 12 mm 板材」忽略了受控的腐蝕基礎、負公差、成型、其他載荷和特定規範要求。

更改一個係數只會掩蓋而非修復這些根本原因。已移除不受支持的公式引擎、預設值、自動結果和規範符合性語言。

此清單為範圍提醒，不能替代任一規範。負責的經批准計算必須確定適用內容，包括：

管轄權、確定的 governing 規範/版本/增補和元件範圍；
設計、操作、測試和外部壓力；溫度和同時發生的載荷情況；
元件幾何形狀、直徑/厚度慣例、封頭、開口、接管、支撐和不連續性；
材料規格、產品形式、溫度相關的允許應力基礎和退化機制；
接頭類別、焊接細節、檢查範圍、適用係數和製造路徑；
腐蝕/侵蝕裕度、設計壽命、材料負公差、成型變薄和計入的最小厚度；
外部壓力穩定性、局部載荷、風/地震/死重、熱效應、疲勞、蠕變、斷裂和循環使用（如適用）；
補強、檢查、無損檢測、壓力測試、超壓保護、文件和授權批准。

定義控制： 裕度是加到計算厚度上、從可用厚度中扣除、嵌入其他地方或由其他規則處理，本頁面無法決定。請嚴格遵循授權規範和經批准的專案計算。

ASME BPVC 第八卷，第一分卷

官方 ASME BPVC.VIII.1-2025 產品頁面描述了其範圍內容器的設計、製造、檢查、測試和認證要求，包括材料/製造要求以及強制性和非強制性附錄。此公開範圍確認了為何少數通用方程式無法確立符合性；詳細規則需要授權存取。

EN 13445-3

官方國家標準機構頁面 NBN EN 13445-3:2026 將其標識為自 2026 年 7 月 2 日起生效，取代 NBN EN 13445-3:2021+A1:2026。其範圍涵蓋 EN 13445-1:2026 所規範的非受壓容器設計，並由 EN 13445-2:2026 下的鋼材製造。詳細規則仍受授權保護，且必須確認適用的國家採用/管轄權。

長度轉換

NIST SP 811 附錄 B.8 列出 1 英吋 = 0.0254 公尺，並以粗體標記精確係數。因此 1 in = 25.4 mm，且官方單位檢查 0.5 in = 12.7 mm 是精確的。

來源和生命週期狀態存取於 2026 年 7 月 13 日。未經授權文本，不主張任何 ASME/EN 條款編號、表格數值或公式。

否。先前不受支持的公式引擎已移除。僅輸入已由確定的經批准授權規範計算確立的數值。

僅限受控計算明確要求在同一元件位置和厚度基礎上進行算術相加的項目。零是有效的。不要輸入通用的腐蝕數值。

僅當經批准的流程明確允許在扣除所有適用的公差、成型和其他扣除後，將該確切數值計入時。本頁面無法做出該決定。

否。它僅是三個輸入厚度記錄之間的關係。規範計算和每個 governing 設計、製造、檢查、測試和批准要求仍屬外部。

其正確數值取決於確切的規範版本、材料/產品形式、溫度、接頭/檢查範圍和其他授權規則。通用預設值產生了虛假確定性。