AFT Blog
The Opposite of Good Vibrations - Evaluating FIV, AIV, FIP Guidelines from AFT Fathom and AFT Arrow
Learn how to use AFT Fathom and AFT Arrow to help calculate the Likelihood of Failure (LOF) for Flow Induced Vibration (FIV), Acoustic Induced Vibration (AIV), and Flow Induced Pulsation (FIP) in accordance with Energy Institute Guidelines to avoid v...
It's a Pump! It's a Turbine! It's a Pump as Turbine!
Pumps and turbines may serve opposite purposes, but fundamentally, they operate under the same principles. Both pieces of equipment convert between usable work and fluid energy, and both often use an impeller to make the conversion. Differences betwe...
What Is Transient Analysis?
You're tasked to perform a transient analysis of a piping system and it would be really helpful if there was a good software tool out there to help you. Well, you've come to the right place because AFT has great solutions! ...
Know Your Pump & System Curves - Part 3
In the final "Know Your Pump & System Curves" blog series, I am going to discuss the complexities behind pump vs. system curves for systems with pumps in series and parallel configurations. Multiple pumps in series configurations are relatively s...
Digital Twin – Identical or Fraternal?
When I was a child, I was jealous of twins. I thought how cool it would be to have a twin. I had twin cousins a few years older than I was that I saw on a frequent basis. I always got them confused. Which one was Roger, and which one was Ronny? A buz...
That Valve’s Got Character – Applying Pre-defined Characteristic Curves
Valves are often oversimplified during modeling. Understandably, defining a valve with its range of Cv at various open percentages requires much more information than an engineer may have during the initial design phase. However, just like handbook d...
Sometimes design engineers will install a screen to protect equipment like centrifugal pumps. Screens are available in a variety of configurations, each with its own head loss characteristics. AFT Fathom provides a screen junction that allows users to choose from four different screen types: Perforated Plate (Sharp-Edged)Perforated Plate (Round-Edged)Circular WireSilk Thread Screen This article primarily discusses thin-walled, sharp-edged perforated plates with uniform diameter holes. Every screen has an open flow area that allows the working fluid to bypass the screen while restricting any foreign objects that are not able to pass through this area. The open flow area is typically comprised...
Ensuring your pump has sufficient net positive suction head available (NPSHA) is essential to reliable pump performance. For positive displacement pumps, this includes accounting for acceleration head, which will reduce a pump's NPSHA. What is acceleration head? Acceleration head is the energy required to change the velocity of the liquid in the sy...
An amusing minor coincidence happened to me in writing this President's Perspective. I have been thinking for a while about writing an update to a blog I wrote some time ago about what various world languages call the English word waterhammer. I happened to decide that this was the month I was going to update my previous blog. And when I looked bac...
Improve Safety & Accuracy in Pipe Force Predictions ASME B31 piping code requires engineers to consider loads on pipes from waterhammer, steam hammer and other fluid transients. In principle, this means using Newton's Second Law which he published over three centuries ago. In 1687 to be specific. And in Latin if you want to read it in its...
Today I flew into Houston for probably the 30th time. To many, Houston represents the fading past of an unsustainable energy monstrosity. To others it represents ingenuity, opportunity and a sort of pride at being the backbone in the development of modern civilization. The reality is we all need energy. Our ancestors built water wheels to harness e...
Many AFT users have come across the message that a reference pressure is needed when attempting to run a model but do not often know how to handle it. Why is it showing up? What can they do to fix the issue? Before going too far, it is important to understand the problem is a limitation of physics and math, not of AFT software. We will wo...
Evans Goodling? An engineer? Who is that? Until last month I had almost no idea. The ASME 2022 PVP conference in Las Vegas last month changed that. There I met someone who knows Goodling personally and worked with him in ASME for many years. He gave me some background on how Goodling came up with his steam hammer load prediction method. Which is wh...