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Applications · Welded Tank Analysis

The shell-to-bottom joint of your tank, justified by the fatigue of each fill cycle

The thickness of the shell-to-bottom weld and the nozzle welds is not set by experience: it is set by the fatigue accumulated in each fill cycle. Knowing that fatigue before the weld fails is what separates a justified design from one inherited from the previous.

Propose a part for a pilot case
Demonstration on generic geometry: tank shell-to-bottom joint with weld stress and fatigue with finite elements. (1/2)Demonstration on generic geometry: tank shell-to-bottom joint with weld stress and fatigue with finite elements. (2/2)
Demonstration on generic geometry: tank shell-to-bottom joint with weld stress and fatigue with finite elements.

What we calculate

  • Shell-to-bottom joint fatigue (FEM)

    Stress and fatigue of the shell-to-bottom weld under liquid-level load cycles, wind or seismic loads, to EN 14015, EN 1993-1-9 and IIW.

  • Nozzles and reinforcements (FEM)

    Hot-spot stress at the nozzle weld and at reinforcement welds, to IIW.

Demonstration on generic geometry: tank nozzle with hot-spot stress at the weld with finite elements. (1/2)Demonstration on generic geometry: tank nozzle with hot-spot stress at the weld with finite elements. (2/2)
Demonstration on generic geometry: tank nozzle with hot-spot stress at the weld with finite elements.

Standards we work with

  • EN 14015We calculate to: vertical cylindrical welded steel tanks for liquids at ambient temperature
  • API 650We calculate to: storage tanks for projects with Anglo-Saxon or petrochemical clients
  • EN 1993-1-9 . IIWWe calculate to: fatigue of welded joints
  • ISO 3834We support your certification: quality requirements for fusion welding
  • Is fatigue calculation mandatory for a tank?

    EN 14015 does not require fatigue verification in every case; when filling is frequent or your client requests it, we calculate it to EN 1993-1-9 and IIW.

  • We have been building the same design for decades with no failures.

    Fatigue acts silently and may take years to appear. Documentary verification also protects the manufacturer against a potential civil liability claim.

  • Doesn't our inspection body (OCA) cover this?

    The inspection body checks execution quality (welds, NDT tests); it does not issue a fatigue calculation report. The Zytel report provides that document.

  • Do you work with API 650?

    Yes. For projects with clients requiring API 650, we calculate under that standard. The report is issued by Zytel; professional-body endorsement (visado) is arranged on request.

Pilot case

Propose a part for a pilot case

Send us the drawing or a description of the part, its material and how it works. We will tell you what we can calculate, with which data and in what time frame. The pilot case ends with a signed report.

Write to ingenieria@zytel.es

Phone: 976 14 18 19