Author(s): Trey Walters
Linked Author(s):
Keywords: AFT Impulse
Abstract:
The AFT Impulse modeling software has a long history of applications in municipal and industrial systems. This session will begin with a discussion of the assumptions used in AFT Impulse and the scope of capabilities. For above ground piping the transient hydraulic forces must be understood so proper pipe supports can be designed. An overview of assessing transient pipe forces will be given. Moving from simplified academic examples to real world systems can involve an immense jump in complexity. A complicated LNG marine offloading system will be discussed with 30+ transient events which occur within 30 seconds. Finally, two case studies will be reviewed. The first is a municipal water pumping station upgrade in Barcelona, Spain where the engineers measured the transients after pump trips using different check valve designs. The second is an industrial system in a Jamaican alumina refinery “Digester Blow-Off” system pumping a caustic, high- temperature alumina slurry. A manual valve experienced a catastrophic break of the valve stem. This led to a slam of the valve disk which sent a surge transient wave back towards the upstream pump and exploded the pump casing.
Year: 2025