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Codes & Standards · Storage Tank Design (API 650)

Storage Tank Design (API 650) Codes & Standards Explained

Buyers of storage tank design (api 650) tend to ask the same questions: what is actually included, what does it cost, which standards apply and how do you pick a reliable partner? This article answers all four with the level of detail your project team needs.

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Key takeaways3 min read4 sections

The short version

  1. 1The standards that govern storage tank design (api 650)Storage Tank Design (API 650) is governed by ASME Sec VIII Div 1/2, EN 13445, PD 5500, API 650, TEMA, API 660.
  2. 2How code compliance is demonstratedCompliance is shown through documentation, not assertion. Your package should include:
  3. 3Common compliance mistakesThe most frequent compliance failures we see in storage tank design (api 650) are edition drift (working to a superseded code edition), mixing code systems mid-package, and missing project-specific overlays.
  4. 4Working across multiple jurisdictionsGlobal projects often need one package that satisfies several jurisdictions.
  5. 5The bottom lineName the edition, not just the code family — ASME Sec VIII Div 1/2 compliance is demonstrated through a documented design basis, calculations and a checker's sign-off.

Quick answer

In short, storage tank design (api 650) means designing vertical, horizontal, fixed and floating roof tanks to API 650 and related codes. The work is governed by ASME Sec VIII Div 1/2 and EN 13445, executed on licensed PV-Elite and checked against a documented QA checklist before issue.

The standards that govern storage tank design (api 650)

Storage Tank Design (API 650) is governed by ASME Sec VIII Div 1/2, EN 13445, PD 5500, API 650, TEMA, API 660. Which one leads depends on the project location and the owner's specification — a US refinery package and a European commercial building may need the same discipline executed to entirely different rules.

Beyond the headline code, most projects layer client specifications on top: operator standards (Shell DEPs, Saudi Aramco SAES, ADNOC), fabricator preferences and local authority requirements. A good storage tank design (api 650) partner maps all of them into a compliance matrix at kick-off.

How code compliance is demonstrated

Compliance is shown through documentation, not assertion. Your package should include:

  • Design basis / basis-of-design note referencing the governing code and edition.
  • Calculation reports with load combinations and acceptance criteria.
  • Drawings flagged with the applicable code and material grades.
  • A documented checker's review with sign-off.
  • Revision-controlled transmittals so the latest code-compliant issue is unambiguous.

Common compliance mistakes

The most frequent compliance failures we see in storage tank design (api 650) are edition drift (working to a superseded code edition), mixing code systems mid-package, and missing project-specific overlays. Each is avoidable with a kick-off compliance matrix and a senior review gate.

Working across multiple jurisdictions

Global projects often need one package that satisfies several jurisdictions. We deliver storage tank design (api 650) to ASME Sec VIII Div 1/2 and EN 13445 routinely and maintain checklists for each, so multi-code packages are reviewed against every governing standard, not just the primary one.

Storage Tank Design (API 650) — codes & standards

Storage Tank Design (API 650) Codes & Standards Explained: FAQ

Which code applies to storage tank design (api 650)?

In short, storage tank design (api 650) means designing vertical, horizontal, fixed and floating roof tanks to API 650 and related codes. The work is governed by ASME Sec VIII Div 1/2 and EN 13445, executed on licensed PV-Elite and checked against a documented QA checklist before issue.

Which software is used for storage tank design (api 650)?

We deliver on licensed PV-Elite, Codeware COMPRESS, Autodesk Inventor and issue native files plus PDF, DWG and IFC on request.

Which standards do you follow for storage tank design (api 650)?

We work to ASME Sec VIII Div 1/2, EN 13445, PD 5500, API 650, TEMA, API 660, plus client specifications such as Shell DEPs and major operator standards.

How long does a storage tank design (api 650) package take?

Small packages are typically delivered in 3–7 working days; larger scopes are split into phased submissions agreed at kick-off.

How do I get a quote for storage tank design (api 650)?

Send your drawings or scope through our quote form — a senior engineer reviews them and returns a fixed-price proposal within 24 hours, free and without obligation.

Code by code

The standards behind a storage tank design (api 650) package

Each standard below governs a different slice of the scope. A compliant package names the edition of every one that applies and carries the evidence in the transmittal.

Multi-jurisdiction projects need the package reviewed against every governing standard — not only the primary one named in the contract.

  1. ASME Sec VIII Div 1/2Global

    Governs pressure vessel design by rule (Div 1) or by analysis with higher allowable stresses (Div 2).

    Evidence: a design report stating the division used, MAWP, MDMT and the nozzle load envelope.

  2. EN 13445Europe & UK

    Governs unfired pressure vessels placed on the market under the Pressure Equipment Directive.

    Evidence: a design dossier referencing the PED category, fluid group and conformity route.

  3. PD 5500United Kingdom

    Governs unfired fusion-welded pressure vessels under the UK specification.

    Evidence: calculations naming the construction category and the inspection regime it implies.

  4. API 650Global

    Governs welded above-ground storage tanks — shell courses, roof, annular plate and seismic design.

    Evidence: shell thickness calculations by the one-foot or variable-design-point method plus a seismic check.

  5. TEMAGlobal

    Governs mechanical standards for shell-and-tube exchangers — class R, C or B tolerances and details.

    Evidence: a TEMA-class statement on the datasheet with matching tube layout and baffle details.

  6. API 660Global

    Governs shell-and-tube heat exchangers for refinery and petrochemical service.

    Evidence: a datasheet and mechanical design report covering the purchaser's supplementary requirements.

Work through this

The storage tank design (api 650) checklist

Fifteen points, in the order you will need them — from assembling the enquiry to signing off the final transmittal. Tick them here, or copy them into your own project procedure.

15 checks
01

Before you send the enquiry

Everything a supplier needs in order to price accurately.

02

Proving compliance

Compliance is documented, never asserted.

03

Before you accept the package

Fifteen minutes here saves a fabrication hold.

About this guide

How we know this

Written from delivered work
The guidance here comes from live storage tank design (api 650) packages produced on licensed PV-Elite, Codeware COMPRESS, Autodesk Inventor — not from a content brief.
Checked against the governing codes
Every technical statement is cross-read against ASME Sec VIII Div 1/2, EN 13445, PD 5500, API 650, TEMA, API 660 and the operator specifications our teams work to daily.
Reviewed through the same checker gate
A senior engineer who signs off storage tank design (api 650) deliverables reviewed this article, using the independent-check process every client package passes through.
Revised when the standards move
Articles are re-read and re-stamped whenever a governing code edition, software release or client specification changes materially.

2009

Engineering since

1,200+

Projects delivered

40+

Countries served

60+

In-house engineers

Reviewed by

Static Equipment Design practice

Senior engineer, SES static equipment design team

Last reviewed
25 February 2026
Review gate
Independent checker

Working toolset

PV-EliteCodeware COMPRESSAutodesk Inventor

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