HISC – Automatic Strain Criteria

Hydrogen Induced Stress Cracking (HISC) is a problem that duplex and super duplex material may experience when cathodic protected in seawater. The hydrogen of the seawater may diffuse into the material and may lead to cracking. DNVGL-RP-F112 describes diffusion rates, acceptance criteria for both stress and strain levels. HISC is often one of issues that […]

Stressman Enhanced Flange Method

Stressman Engineering has over the time analyzed plenty of ASME B16.5 flanges in accordance with ASME VIII and the patented flange leakage criteria developed by Coade (now Hexagon). We are working on structuring the findings. Our aim is to generate a simple lookup table that should be used with the Kellogg’s flange method. Sing up […]

White paper – Stresses in bends – Rev 2

NIRAS and Stressman has performed a joint study to better understand induction bends. In the study we have performed several parametrical analyses and benchmarked a non-linear analysis against a real burst test. The general conclusion is that simple hand calculations per ASME B31.3 Chapter II is sufficient for many topside applications, as well as subsea […]

SIFs and stresses in branch connections at different branch angles

This rough and shallow analysis studies the correlation between stresses, SIFs and connection angles of a 4″ND (WT=5mm) Tee component due to in-plane and out-of-plane bending moment. The reason for the initialization of the report was discussion thread in the LinkedIN community and our curiosity.  Click here to download.

SIFs and stresses in bends at different bend angles

This rough and shallow analysis studies the correlation between stresses, SIFs and bend angles of a 4″ND (WT=5mm) pipe bend due to in-plane bending moment. The reason for the initialization of the report was discussion thread in the LinkedIN community and our curiosity. More details on SIFs are also given in the whitepaper about induction […]

Vortex Induced Vibrations on Complex Piping Structure

Sondre Luca Helgesen at Stressman Engineering performed a study in the spring of 2011 of how vortex induced vibrations does impact on complex subsea piping structures. The aim of the study was to compare DNV’s standards that are mostly based on long riser geometries. The study was performed as a Master’s Thesis at Telemark University […]