ASME Northern Alberta Section: Waterhammer and Surge - Conceptional Foundations to Analysis and Mitigation Through Software

Description

The ASME Northern Alberta Section (NAS) invites you to join us as Nick Vastine of Applied Flow Technology explores the theory of waterhammer and surge in piping systems and the real-world analysis performed in the application AFT Impulse. Pressure surge results from sudden changes in flow, converting a fluid’s kinetic energy into large changes in pressure. Surge is inevitable in all piping systems, but its damage can be controlled by understanding surge’s cause and effect. Learn how to analyze surge in your own systems using tools built by engineers, for engineers. Nick will overview the fundamentals concepts that drive pressure surge in a transient event including basic conservation of energy, wave speed, and the instantaneous pressure rise equation. Understanding the cause of surge helps explain its dangers including overpressure, pipe stress, cavitation and vacuum collapse. We will model a valve closure event to demonstrate the process of a surge analysis, while further building foundations such as the waterhammer cycle, effective closure time, and communication time. ASME Codes B31.3 and B31.4 in-part codify the need for surge analysis, requiring engineers consider the maximum potential pressure in the system which cannot exceed 10% of the pipe’s design pressure. AFT Impulse can model these surge considerations to visually understand the cause and effect of surge, guiding engineers toward a mitigation strategy. We will model a valve closure event to demonstrate the process of a surge analysis, while further building foundations such as the waterhammer cycle, effective closure time, and communication time. Valve closures are the most cited cause of surge, but pump start-ups or trips similarly cause concern. Reverse flow following a pump trip can also damage components, and protection methods like check valves might introduce more problems than they solve. The concerns from these transient events and more can be modeled in AFT Impulse. By understanding the cause of surge, we similarly understand the effect and how to mitigate these concerns. Spoiler alert: a longer valve closure does not guarantee reduced surge pressure. We will review surge vessels, safety valves, and changes to operation that minimize the risk of surge. Whether you are a surge expert or have only heard waterhammer in your pipes at home, you’re certain to learn something new. Visit the link above to learn more and register. We hope you can attend!