Transient Pipe Forces can reach magnitudes upwards of 10,000 lbf (50 kN) during routine operations such as valve closures or pump trips. The only practical way to safely and confidently calculate such forces is with fully-featured fluid transient simulation tools like AFT Impulse and AFT xStream. Prediction of transient forces from the results of such simulations can be deceptively complicated. In essence, the calculation is simply an application of Newton’s Second Law, but the details of this application are full of potential pitfalls. Fortunately, AFT Impulse and AFT xStream can handle this complexity by delivering transient force results with very few simplifying assumptions from only simple inputs.
The basics of the theory behind transient force calculation, a few problems with traditional or simplified methods, and a demonstration of calculating forces with AFT Impulse and AFT xStream is presented.