Accumulator Capacity Calculator

An accumulator is a metallic ball-like structure, internally separated into two compartments by a man-made rubber partition. The top compartment holds the system’s fluid under pressure, while the bottom compartment is filled with nitrogen or air.

A cylindrical variant of the accumulator is also utilized in high-pressure hydraulic systems. Multiple accumulators can be found in the hydraulic systems of numerous aircraft, including a primary system accumulator and a backup system accumulator. Additional accumulators may also be found in different subsystems.

Hydraulic accumulator

Here is a more detailed explanation of the parts of the hydraulic accumulator in the image:

  • Hydraulic system pressure: This is the pressure of the hydraulic fluid in the hydraulic system.
  • Diaphragm: The diaphragm is a flexible membrane that separates the hydraulic fluid from the pressurized gas.
  • Screen to prevent extrusion: This screen prevents the diaphragm from extruding through the gas servicing valve.
  • Rigid button or disc to prevent extrusion: This button or disc also prevents the diaphragm from extruding through the gas servicing valve.
  • Hydraulic fluid: This is the fluid that is stored and transported in the accumulator.
  • Nitrogen or air: This is the pressurized gas that drives the hydraulic fluid out of the accumulator.
  • Gas servicing valve: This valve allows the gas pressure in the accumulator to be adjusted.
  • Retaining plug: This plug seals the gas servicing valve.

Accumulator Types

There are two main types of hydraulic accumulators: bladder accumulators and diaphragm accumulators. Both types work on the same basic principle, but they use different methods to separate the hydraulic fluid from the gas.

In a bladder accumulator, the hydraulic fluid is separated from the gas by a flexible bladder. The gas is usually nitrogen, which is an inert gas that does not react with the hydraulic fluid.

Bladder Accumulator

In a diaphragm accumulator, the hydraulic fluid is separated from the gas by a flexible diaphragm. The diaphragm is usually made of a synthetic rubber material.

Diaphragm Accumulator

The gas in the accumulator is pre-charged to a pressure that is higher than the operating pressure of the hydraulic system. This pre-charge pressure provides the force to push the hydraulic fluid out of the accumulator when needed.

Accumulators are used in a variety of hydraulic systems for a variety of purposes. Some of the most common uses for hydraulic accumulators include:

  • To provide energy for auxiliary systems. Accumulators can be used to provide energy for auxiliary systems, such as brakes, steering, and winches. This can be useful in applications where the main hydraulic system is not always running.
  • To absorb shock and vibration. Accumulators can be used to absorb shock and vibration caused by sudden changes in load or pressure. This can help to protect the hydraulic system from damage.
  • To maintain system pressure. Accumulators can be used to maintain system pressure when the hydraulic pump is not running. This can be useful in applications where the hydraulic system must be able to operate even when the engine is not running.
  • To smooth out flow pulsations. Accumulators can be used to smooth out flow pulsations caused by the hydraulic pump. This can help to improve the performance of the hydraulic system and extend the life of the components.

Accumulator Capacity Calculator

The calculations used in this calculator are based on ideal gas laws and assume that the gas and fluid are not interacting. In real-world applications, these assumptions may not be fully accurate, and additional factors like temperature, fluid compressibility, and gas-to-fluid ratio may need to be taken into account. 

Now, let’s describe each input in the formula:

  1. BC (Accumulator Container Volume per capacity in gallons): This is the physical volume of the accumulator container. It can be found on the manufacturer’s specifications sheet or tag on the accumulator itself.
  2. Pp (Pre-charge Pressure in psi): This is the initial gas pressure in the accumulator before any fluid is sent to it. The pre-charge pressure is usually set by the manufacturer and can often be found on the product specifications sheet. In some cases, it may be necessary to manually measure this pressure using a pressure gauge.
  3. Ps (System Pressure in psi): This is the pressure of the system when it is running under normal operating conditions. In many cases, the system pressure is set by the pressure relief valve and can be found in the system’s operational manual or by using a pressure gauge.
  4. Pf (Final Pressure in psi): This is the maximum pressure the accumulator will reach when it is fully charged. This value is set based on the system’s requirements and can be found in the system’s operational manual. In practice, it may be necessary to adjust the final pressure to account for changes in system demand or energy requirements.
Enter Accumulator Container Volume per capacity (gallons):

Enter Pre-charge Pressure (psi):

Enter System Pressure (psi):

Enter Final Pressure (psi):

Hydraulic accumulators are an important component of many hydraulic systems. They provide a variety of benefits, such as improved performance, increased reliability, and reduced maintenance costs.

how does a/c accumulator work

The A/C accumulator, a critical component in the air conditioning system of your vehicle, operates by storing excess refrigerant to prevent any potential damage to the compressor. It basically functions as a filter, trapping moisture and debris that could otherwise damage your A/C system. The accumulator also serves to separate gas and liquid state refrigerant, allowing only gas to flow towards the compressor, ensuring smooth function and longevity of your air conditioning system. Understanding how an A/C accumulator works helps in maintaining optimal car performance and comfort, especially during warmer months.

what is (an does) an accumulator in hydraulic system

It is designed to regulate the performance of the system by maintaining hydraulic fluid pressure, absorbing shock, and compensating for fluid leaks. Accumulators play a vital role in ensuring the efficiency and longevity of hydraulic systems, making them indispensable in a wide range of industrial applications. From construction machinery to automotive brake systems, accumulators are a keystone of hydraulic technology, driving optimal functionality and delivering high-performance results.


What are the key differences between bladder and diaphragm hydraulic accumulators?
The main difference between bladder and diaphragm hydraulic accumulators lies in their internal design and construction. Bladder accumulators use a flexible bladder to separate the hydraulic fluid from the gas, whereas diaphragm accumulators employ a flexible diaphragm to achieve the same separation. While both types operate on the same principle, bladder accumulators are more suitable for high-pressure applications, whereas diaphragm accumulators are better suited for low-to-medium pressure systems.
How do hydraulic accumulators improve system performance and reliability?

Hydraulic accumulators improve system performance and reliability by providing a buffer against pressure fluctuations, absorbing shock and vibration, and supplementing pump flow during peak demand periods. This results in smoother system operation, reduced wear and tear on components, and increased overall system efficiency. Additionally, accumulators help to maintain a consistent system pressure, which reduces the likelihood of component failure and extends system lifespan.

What are the benefits of using multiple accumulators in a hydraulic system?

Using multiple accumulators in a hydraulic system offers several benefits, including increased system redundancy, improved overall system reliability, and enhanced performance. In aircraft hydraulic systems, for example, multiple accumulators provide backup capacity in case of primary system failure, ensuring continued safe operation. In other applications, multiple accumulators can be used to serve different subsystems or to provide additional capacity during peak demand periods.

How does accumulator capacity affect system performance and efficiency?

Accumulator capacity has a direct impact on system performance and efficiency. An accumulator with insufficient capacity may not be able to provide adequate pressure and flow support, leading to reduced system performance and efficiency. Conversely, an oversized accumulator can lead to increased system complexity, higher costs, and potential reliability issues. Proper sizing of the accumulator is critical to ensure optimal system operation and efficiency.

What are the key factors to consider when selecting an accumulator for a hydraulic system?

When selecting an accumulator for a hydraulic system, key factors to consider include system pressure and flow requirements, operating temperature range, fluid compatibility, and physical space constraints. Additionally, consideration should be given to the type of accumulator (bladder or diaphragm), its materials of construction, and any specific certifications or regulatory requirements (e.g., aerospace or industrial applications).

How can an accumulator capacity calculator help optimize hydraulic system design?

An accumulator capacity calculator is a valuable tool for optimizing hydraulic system design by ensuring that the accumulator is properly sized for the specific application. By inputting system parameters such as pressure, flow rate, and fluid properties, the calculator can determine the required accumulator capacity, taking into account factors such as pressure fluctuations, flow demand, and system efficiency. This helps to prevent undersizing or oversizing the accumulator, ensuring optimal system performance and efficiency.