When I wrote AFT Impulse 1 back in 1996, I slipped in an undocumented feature to make it capable of modeling the first waterhammer project I did in industry. Since then, this feature had a secret (i.e., undocumented) way of being enabled. AFT Impulse 8 will be released any day, and we have finally made this feature accessible to all. In the User Op...

In June 2020, AFT's Reinaldo Pinto presented the webinar Calculating Transient Forces for Pipe Stress Analysis. The webinar focused on generating unbalanced forces due to surge in AFT Impulse and exporting them to CAESAR-II. During the webinar, 28 questions were asked. Below are the responses.  Download the presentation: www.aft.com/...

At the time of writing, AFT Impulse 8 is right around the corner. We are proud to boast of new capabilities to give you an even better user experience with transient analysis. AFT Impulse 8 showcases new features never seen before, and ones only hinted at with the releases of AFT Fathom 11 and AFT Arrow 8. Here, we have laid out the top 5 new featu...

Really? Another blog about features in AFT software? Yes, really. And there is a good reason for it. Because this new feature in AFT Impulse 8 will change your life. Well, it may not change your life, but it will forever change how you do your waterhammer analysis. I am talking about the new multi-scenario graphing and animation feature. This brand...

Any time a rapid transient occurs in a piping system, there is a chance for unexpected surge to impact the system. Though system shutdowns account for many surge events, pump startups can cause water hammer as well. For this blog I am going to cover the basics of setting up pump and valve transients for the startup case in AFT Impulse 7, as well as...

In any complex piping system, one of the most serious scenarios considered during a safety or HAZOP study is over-pressurization. If the pressure in the system reaches a high enough pressure, rupture can occur, leading to expensive repairs, significant system downtime, and even loss of life. In most cases, proper use of relief valves can mitigate o...

 I have received questions from clients using AFT Impulse where they ask something like "I closed this valve. Why is the maximum pressure spike way over there and not at the valve?" This comes from years of developing a "common sense" adapted to steady-state flow. With steady flow, a change between states of equilibrium has a local effect that...