October 1, 2020

Article author
Shaju Sachin
  • Updated

What's New

  • Added a new failure mechanism calculator for soil corrosion and thermal fatigue.
  • Added a new section to the Edit Facility screen to manage facility-level calculation settings. You can also manage these settings per scenario.
  • No longer allowing deletion of a unit or area if they are being used in a Facility Model Diagram.
  • Now extending the Probability of Failure (PoF) Over Time curves to the end of the calculation date range, even if it reaches 100%.
  • Removed the warning around not having a repair/replace task for an asset when running PoF calculations.

API 581 Calculations

As part of this we release, we are working toward building an API 581 compliant risk calculator. There are several changes that we have included in this release and many more to come.


API 581 defines four governing probabilities that we will be implementing PoF Models for. The models and their status are listed below:

  • Stress Corrosion Cracking Damage Factor (API 581) - Implemented in a previous release
  • External Damage Factor (API 581) - Implemented this release
  • Internal Thinning Damage Factor (API 581) - Planned for a future release
  • Brittle Fracture Damage Factor (API 581) - Planned for a future release

As part of the implementation of the External Damage Factor (API 581) PoF Model, we have made the following changes:

  • Renamed the Component Type field that was on the Thickness CML to Geometry Type and updated the options to align with API 581.
  • Moved the Cladding Thickness (In) field from the asset/component level to the Thickness CML level and renamed the Nominal Thickness (In) field to Base Material Thickness (In). This eliminates the previous confusion around what the nominal thickness was for cladded assets/components.
  • Added Yield Strength (psi), Tensile Strength (psi), and Allowable Stress (psi) fields on the Thickness CML. In the future, we will enable Newton to look these values up.
  • Added the ability to link a Thickness CML, enter a Data Confidence, and run the External Damage Factor (API 581) PoF Model


Consequence of Failure

API 581 provides guidance on how to calculate the consequence of a failure in five different areas: personnel injury, environmental, component damage, surrounding area, and business interruption. In order to enable the ability to perform API 581 along side Newton consequence calculations, we are creating a new Consequence of Failure (CoF) Assessment tab in the ARA screen. We will continue to build out this feature in the coming releases. This is what has been done as part of this release:

  • Removed Slurry as a valid option for fluid phase of a stream.
  • Added the ability to group asset/components into inventory groups.
  • Added new Detection System Rating, Isolation System Rating,  and Mitigation System fields at the asset level.


Probability of Failure <-> Hazard Rate

Newton reports probability results in terms of probability of failure, which is how likely you are to have failed on a given date. However, a lot of the industry reports probability results in terms of Hazard Rates, which is how many failure events per year might happen on an asset/component. While these two probability numbers are related, they are fundamentally different measures. Because of this, we have implemented a feature to toggle between PoF and hazard rate. This feature is available on all current PoF Models and will be built into future models.


What's Fixed

  • Fixed an issue where the Today line would not stay in the same place on the results charts when the browser window was resized.
  • Stopped allowing the import of inspection and task data onto the asset level if that asset has components. Assets with components should have all of their Asset Risk Analysis (ARA) data stored at the individual component level.
  • Fixed an issue where selection of a PoF Model on a failure mode was required.
  • Fixed issues around errors that would not display correctly from the Failure Mode or Failure Mechanism cards in the ARA.
  • After adding Insights, you no longer have to refresh the page to see the Insights load on the top navigation bar.
  • Adjusted areas that allowed the Reviewer role to edit assessment data.
  • Corrected an issue in the logic for the Wet H2S Damage (Blistering/HIC/SOHIC) Failure Mechanism calculator.
  • Fixed an issue where clicking on the Area/Unit/System/Sub-system/Component icons to open System Model would give an error.
  • Corrected an issue where the ARA results would errantly report that a component would have a predicted unplanned event even though the PoF Chart shows no failure in the calculation date range.
  • Fixed an issue where errant decimal places would be shown in the CML Readings grid.
  • Fixed the issue where the download data option was not working for the Risk Over Time chart in the ARA results.
  • Fixed an issue in the Stress Corrosion Cracking Damage Factor (API 581) PoF Model where the hazard rate would errantly go to zero after a performed inspection.
  • Fixed an issue where failure mechanisms with pitting as a damage mode would cause the PoF calculations to fail.
  • The PoF Models will no longer consider CML data that is before the asset/component's install date.

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