Water hammer is actually a traveling pressure wave. It was initiated by the rapid stoppage of an incompressible flowing liquid. For example, the pounding of process piping usually occurs due to rapid valve closure or when large steam bubbles are introduced into water and the water rapidly collapses the steam bubbles. These pressure waves reflect back-and-forth between the interior walls of a piping system, reinforcing themselves as succeeding waves encounter the reflected waves. They can become so energetic that catastrophic structural damage could occur.

The CRV® proves extremely useful in controlling water hammer. Dramatic improvements were seen in a piping circuit with four elbows between the supply line and the shut-off valve where the wall static pressure with and without CRV®s was measured. The results indicate that with a CRV® in place upstream of each elbow, the amplitude of the peak pressure pulse was 49% of that without CRV®s.

The CRV®s geometric features prove extremely useful in controlling water hammer. When fluid is flowing in the forward direction, the CRV® is passive and offers little pressure drop, but when the fluid travels backwards, it will exhibit a high pressure drop and not remain attached to the CRV® vanes, as shown below in figure a. The high drag footprint for backward flowing fluid and pressure waves is shown below in figure b, and acts as a passive damper for reverse flow pressure waves, thus controlling water hammer.



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Our flow conditioners are custom made to specifically address each piping issue offering the greatest achievable flow correction.