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How the Common Rail Pressure Accumulator Works

Model: (Various brands) Various
Part: Checks and maintenance

Video tutorial

This video explains how the pressure accumulator (commonly referred to as the "rail") of the Common Rail works: its function is to accumulate diesel at very high pressure, sent by the high-pressure pump, and distribute it uniformly and instantaneously to all injectors.

The pressure can easily exceed 1,600 bar, and the rail acts as a "hydraulic flywheel" dampening the pulsations generated by the pump.

From here, rigid pipes connect the rail to each injector, supplying fuel at the same pressure to all injectors, coming from a common volume (hence the name "Common Rail") and allowing for fine atomisation of the diesel and precise control of the quantity and timing of injection.

It is equipped with a pressure sensor, a pressure relief valve, and a pressure regulator.


Posted on 24 April 2026 by ScegliAuto


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