1. Understand the Functions of the Accumulator
Accumulators can serve various functions in a hydraulic system, including:
Energy Storage: Store hydraulic energy to be released when needed.
Shock Absorption: Cushion shocks and dampen pulsations.
Pressure Maintenance: Maintain pressure in the system during pump idle or failure.
Leakage Compensation: Compensate for fluid leakage in the system.
2. Determine System Requirements
Operating Pressure: Identify the maximum and minimum operating pressures of the system.
Fluid Volume: Calculate the volume of fluid required to be stored or released by the accumulator.
Temperature Range: Determine the operating temperature range of the system.
3. Select the Type of Accumulator
There are several types of accumulators, each suited for different applications:
Bladder Accumulators: Suitable for high-flow applications and provide rapid response.
Diaphragm Accumulators: Ideal for low to medium flow applications and compact spaces.
Piston Accumulators: Suitable for high-pressure applications and large fluid volumes.
Spring Accumulators: Used in applications requiring low to medium pressure with steady force.
4. Size the Accumulator
Proper sizing ensures the accumulator can meet the system's needs without being oversized or undersized:
Pre-Charge Pressure (P0): The initial gas pressure when the accumulator is empty of hydraulic fluid.
Maximum Operating Pressure (P1): The highest pressure the system will reach during operation.
Minimum Operating Pressure (P2): The lowest pressure at which the system will operate.
The volume (V) of the accumulator can be calculated using the formula: V=V0⋅(P1−P2)P2−P0V = \frac{V_{0} \cdot (P_{1} - P_{2})}{P_{2} - P_{0}}V=P2−P0V0⋅(P1−P2) Where:
VVV = Required volume of the accumulator
V0V_{0}V0 = Volume of hydraulic fluid to be stored or released
P0P_{0}P0 = Pre-charge pressure
P1P_{1}P1 = Maximum operating pressure
P2P_{2}P2 = Minimum operating pressure
5. Material Selection
Choose materials that are compatible with the hydraulic fluid and can withstand the environmental conditions:
Bladder/Diaphragm Material: Nitrile, Viton, or other elastomers based on fluid type and temperature.
Shell Material: Typically steel, stainless steel, or aluminum depending on pressure requirements and environmental factors.
6. Consider Mounting and Installation
Ensure the accumulator fits within the available space and can be securely mounted. Consider:
Orientation: Some accumulators can be mounted in any orientation, while others have specific requirements.
Accessibility: Ensure there is enough space for maintenance and pre-charge adjustments.
7. Safety and Compliance
Burst Pressure: Ensure the accumulator can withstand pressures beyond the maximum operating pressure for safety.
Regulations: Check for compliance with industry standards and regulations (e.g., ASME, PED).
8. Additional Features
Accessories: Consider accessories such as safety blocks, mounting kits, and gauges for ease of installation and monitoring.
Maintenance Requirements: Choose accumulators that are easy to maintain and service.
9. Cost and Availability
Budget: Consider the cost of the accumulator and ensure it fits within your budget.
Availability: Ensure the chosen accumulator is readily available and that spare parts can be sourced easily.
