From time to time, we re-publish well-received or particularly valuable articles that have previously run on VALVEMagazine.com so that those who might have missed them will be able to catch up on the best of the best. This article, “Flashing and Cavitation” by Bert Evans and Richard L. Ritter III initially ran on August 15, 2015.

Some of the following questions may seem ­unrelated, but they all involve key concepts that explain the sometimes-misunderstood ­phenomena of flashing and cavitation:

Like the superhero that can leap tall buildings, the valve industry is made of steel.

Liquid piping systems are prone to collecting air from incoming fluids, pumps and connections. This air can cause inefficiencies and serious operating problems. Last year, VALVE Magazine published “Why Air Valves are Needed in Water Applications,” which outlined the sources and effects of air in pipelines. This article explains how the various types of air valves operate in liquid piping systems.

Water hammer is a shock wave transmitted through fluid contained in a piping system. The most basic explanation is that water hammer occurs when a fluid in motion is suddenly forced to stop moving. The momentum of the fluid abruptly stopping creates a pressure wave that travels through the media within the pipe system, subjecting everything in that closed system to significant forces.