One of the most important industrial applications of accumulators is in the elimination or reduction of high-pressure pulsations or hydraulic shocks.
Hydraulic shock (or water hammer, as it is frequently called) is caused by the sudden stoppage or deceleration of a hydraulic fluid flowing at a relatively higher velocity in the pipelines. This hydraulic shock creates a compression wave at the location of the rapidly closing valve. This wave travels along the length of the entire pipe, until its energy is fully dissipated by friction. The resulting high-pressure pulsations or high-pressure surges may end up damaging the hydraulic components.
An accumulator installed near the rapidly closing valve as shown in Figure 7.24 can act as a surge suppressor to reduce these high-pressure pulsations or surges.