A Thorough Study Of Hydraulic Accumulators

Hydraulic Accumulators

Hydraulic accumulators are a type of accumulator that has the power to strengthen the working capacity by delivering a smoother and more durable operation service. It mainly can be delivered because the accumulator has the capability to store power that can be used in times of emergency, for example, if an electrical failure ever happens, the power that is saved in the accumulator can be used. 

Bladder Accumulator And Other Types Of Accumulators

The accumulator comes in different types depending on the action it provides. Because of their own structure, they have different capabilities and fulfill the needs of the user accordingly. The accumulators are of three types. 

  • Bladder type hydraulic accumulator: A bladder accumulator is one of the most commonly employed hydro-pneumatic accumulators. This is generally made up of rubber and is fitted in a steel metal vessel. It is filled with nitrogen which makes it applicable.

The gas is adapted into the inlet-outlet valve that is mounted on top of the bladder accumulator. When the pressure plummets, the gas in a compressed form that is situated in the bladder broadens and shoves the stored fluid right towards the hydraulic circuit. 

This accumulator is distributed into the other two types of distributors based on the distribution of the pressure.  

  • Low-pressure bladder accumulators
  • High-pressure bladder accumulators
  • Piston type hydraulic accumulator: This particular piston accumulator uses the techniques used by a piston. They have the ability to regulate with a much higher gas-compression ratio.  The ratio is up to 10:1 and flow rates are higher too as it goes as high as 215 liters per second. 

It can be stated that the maximum pressure utilized by hydraulic fluid that is stocked in the piston accumulator is high along with the acceleration with which the hydraulic fluid is discharged towards the hydraulic system is higher too. 

But there is a negative side, in spite of having a higher velocity and the ability to create more pressure, the piston inside the accumulator can create inner friction which could cause an impact on the reaction speed negatively. 

  • Diaphragm accumulator: Diaphragm accumulators possess a rubber plate or diaphragm that works as a separating element in the accumulator. This particular element can either be combined together between two spherical compartments. 

The compartment that is placed above the diaphragm needs to be filled with nitrogen. The compartment that is placed below the diaphragm is directly attached to the hydraulic circuit. Diaphragm accumulators are smaller compared to two other types of hydraulic accumulators. 

The fluid storage capacities of this accumulator are 0.075 to 4 liters. So if someone is using a hydraulic cylinder with a small accumulator, this is the one. Depending on the structure of the compartment, it can be further divided into two types. 

  • Welded type diaphragm accumulator
  • Threaded type diaphragm accumulator

How Does The Parker Accumulator Function?

The accumulators are usually submitted in the hydraulic systems so that it can preserve energy. It does while maintaining the balance of the force and space so that the pulsation in the system is maintained. The hydraulic system can have any type of accumulator depending on the need of the user. However, there is a pump available in the hydraulic system that supplies energy whenever the need arises. 

The pump is mainly the vessel in which the energy is conserved. Whenever a power surge happens, the hydraulic system delivers them with power that was stored with the help of the accumulator by maintaining an even distribution meanwhile retaining maximum pressure and power from it.  The energy that is to be released from the pump needs to be used instantly, no matter the amount of power needed, it will be dropped by the accumulator. 

It not only has this feature but it also holds the ability to provide power at any time while maintaining the pulsation.  So in other words, the accumulators can be functioned as pulsation absorbers. There is an air dome that is placed in the accumulator which is utilized on the pulsating piston or rotary pumps. 

This particular piston pump is actually a hydraulic piston pump that is notable for storing high pressure. It is used in various places for maintaining the highest amount of velocity and the pressure released. It gives you the freedom to choose the fluid that will be used to create the pressure. There is a  positive displacement pump that stimulates into establishing a high amount of pressure. 

This positive displacement pump creates pressure and they do it by allocating the energy through the fluid that is used to create the tension in the vessel.  If the accumulator does not have a piston pump then there is a high chance that it has a hydraulic vane pump

The hydraulic vane pump has a rotor. This rotor is plugged into the cam. This has two side plates. These side plates are rather known as blades. These blades are fitted in a certain way to create allotted slots of the impeller. So when the rotor or the vanes start twirling, the fluid then enters into the pump taking the help of hydraulic pressure that is created.  

The pressure then shifts taking the help of the centrifugal force which makes its way to the vanes. Through the vanes, it moves towards the discharge port. Many tend to use this particular pump because of the characteristics of having a less noisy result compared to the piston pump. It also results in less pulsation.

Now the task is upon the accumulators to soften the hydraulic hammer as it reduces the shocks that are created in the whole procedure. The process is very noisy which creates many pulsations.  However, to help maintain the balance, the accumulator uses the directional control valve

Directional control valve which is rather known as DCVs is one of the most essential portions of both the hydraulic and the pneumatic systems. It is the DCV that stimulates the fluid flow. The fluid can be hydraulic oil, water, or air but it maintains the flow of the chosen fluid while marinating the balance to stimulate the right amount of power. 

The DCVs generally includes a spool that goes inside a cylinder that is put to activity either mechanically or electrically. The role of the spool is to either halt or approve the flow of the fluid. The DCV maintains the pressure by maintaining the amount of flow that is needed to be released. The accumulator, the piston, the pump, and the DCVs work together to make the hydraulic system functional. 

What Is The Purpose Of Hydraulic Accumulators?

The structure of the accumulators is made in a way that makes it one of the most used parts in the hydraulic system. There are various different purposes of the accumulators that make the task of producing the result very easy and effective. 

  • Stocking the energy: The main purpose of the accumulators is to store the energy. However, they only use 2% of the stored power in a time of need. A small amount of power will be condensed, the power will remain however the volume will reduce. That is why they release less pressure. 
  • Absorbing the pulse: The pumps, vane or piston, absorb the pulses. The pulses are what assures that the power is being delivered. 
  • Cushioning the shock: the power creates a shockwave in the system which further results in the creation of pressure in the system. The accumulator tries to buffer the shock by delivering the fluid in a small amount.

Some Most Asked Questions:

It tries to mitigate the excessive demand for power while managing the integrity of the system as it continues to cushion the harmful shock, absorb the pulse and stock energy.
It has been said that the bladder accumulator comes pre-charged to 80%, however, the piston accumulator should be below 100psi.
Mainly because of the lack of reactive characteristics nitrogen has with other elements present in the system.


Apart from all of these, this accumulator can discharge an excess amount of fluid. The accumulator continues to work together with other parts present in the system to make sure the efficiency of the task. An accumulator is needed in order to maintain the integrity of the hydraulic system meanwhile providing the system with power that they need in times of urgency. 


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