Hydraulic accumulator initial pressure

What is the operating pressure of a hydraulic accumulator?

Most accumulators used within industry are limited to an operating pressure of 3000 psi. Accumulators are available which operate at higher pressures. In general, hydraulic accumulators are pre-charged one half of the maximum operating fluid pressure, this is adequate for most applications.

What is a hydraulic accumulator?

Accumulators will cushion hydraulic hammer, reducing shocks caused by rapid operation or sudden starting and stopping of power cylinders in a hydraulic circuit. There are four principal types of accumulators: the weight-loaded piston type, diaphragm (or bladder) type, spring type, and the hydro-pneumatic piston type.

What is a precharge pressure accumulator?

Its initial gas pressure is called the “precharge pressure.” When the system pressure exceeds the precharge pressure, the nitrogen gas is squeezed, compresses and decreases in volume, letting hydraulic fluid into the accumulator. The accumulator’s fluid volume increases until the system reaches its maximum pressure (P2).

How much psi do accumulators need?

For example, in the circuit shown above, it takes at least 2,000 psi to perform the work, but the accumulators must be filled to a higher pressure so they can supply extra fluid without dropping below the system’s minimum pressure.

What is the precharge pressure of a bladder accumulator?

In energy-storage applications, a bladder accumulator typically is precharged to 80% of minimum hydraulic system pressure and a piston accumulator to 100 psi below minimum system pressure. Precharge pressure determines how much fluid will remain in the accumulator at minimum system pressure. Figure 2.

How does precharge pressure affect accumulator performance?

Precharge pressure forces fluid from the accumulator into the system. Minimum system pressure is reached. The accumulator has discharged its design maximum volume of fluid back into the system. When selecting an accumulator for a particular application, both hydraulic system and accumulator performance criteria should be considered.