TRANSIENT (CIVIL ENGINEERING)

In civil engineering, a 'transient' is used to refer to a water hammer pressure wave. In a pipe network, when a valve or pump is suddenly shut off, a region of high pressure builds up immediately behind the valve/pump. The high-pressure region grows as water, which was initially flowing out of the valve, suddenly becomes stationary. The border of the high-pressure zone is referred to as a pressure wave, or transient.