Initially, these devices were placed on the hydraulic line and it was hoped that the pulsations would enter the accumulator. However, in practice, pulsations bypassed the line leading to the accumulator. But the sizing of the design was difficult and the design was expensive. The pressure drop through the accumulators was also very high and created a problem in some instances. The second chamber is the compressed spring.
Oil freely flows through the compressed spring.
Each chamber is sized to give adequate flow area for the fluid. The complete flow chamber fits into the bladder. This cross section of the Suppressor shows the outer steel shell, the nitrogen charge, the bladder, the oil and the diffuser tube This device, on the other hand, mounts an in-line nitrogen charged noise suppressor at the outlet of the pump. The tuning of the device is achieved by slight adjustments to the nitrogen precharge of the unit, an operation that is somewhat easier than wrapping the piping in sound absorbing tape or enclosing the entire power unit. Usually mounted directly at the pump outlet, the suppressor reduces the noise of any hydraulic power unit before it travels through the piping and radiates off other structural components.