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Accumulator manufacturer -- Nakamura Koki Co., Ltd. | What is an accumulator?

Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Precautions for safe use of accumulators

Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Technical information Top page

Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Selecting an Accumulator

 

Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Technical information

 

Precautions for safely using accumulators

 

  An accumulator is a pressure vessel to accumulate fluid pressure using high-pressure gas. Its improper use or use/modification beyond its design basis is very dangerous. In order to prevent hazards to personnel/property and to ensure your safety, please pay attention to the following instructions:

 

 

1. Selecting an accumulator

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Necessity of compliance with laws and regulations in the country
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  • The accumulator is a pressure vessel using high-pressure gas. Therefore, depending on the place where it is used, it’s working pressure, volume, etc., it may be subject to application of laws such as the High Pressure Gas Safety Act in Japan, the Industrial Safety and Health Act (Class-2 pressure vessel) in Japan, etc. Note this matter when selecting your desired accumulator.

    In addition, if you use an accumulator outside Japan, please note that the accumulator must comply with the laws and regulations of that country.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | accumulator
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  • Please select and use the proper accumulator according to its service conditions (working pressure, required oil quantity, working temperature, fluid type, usage environment, applicable laws and regulations, etc.). Note that an improperly selected accumulator not only produces disappointing results but also has a harmful effect on other equipment.

     

 

2. Installing an accumulator

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Risks of suffering damage due to accumulator bursting etc.
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  • Never carry out welding, tapping or drilling on the accumulator.

    There is a risk of suffering damage due to the accumulator bursting, etc.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | accumulator
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  • Fix the accumulator to a frame or wall surface with bands, etc. It is dangerous to leave an accumulator standing alone because it will not only exert excessive force on each portion in the event of vibration, and earthquake, etc. but also loosen screws.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Danger due to occurrence of abnormal pressure rise
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  • Do not expose the accumulator to external heat. Provide a shield plate when you place the accumulator near heat sources or expose it to sunlight directly. If the sealed gas inside accumulator is heated, the pressure will rise abnormally, and thus become dangerous.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Pressurized liquid piping system using the accumulator
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  • For hydraulic piping systems, please install a pressure control valve as a safety device at the point connecting to the accumulator to keep the pressure from exceeding the max working pressure of the accumulator.

     

 

3. Charging nitrogen gas (pressurization)

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Gas to be charged into an accumulator
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  • Only nitrogen can be used when charging gas into an accumulator. Never use oxygen or flammable gas, as it can result in a risk of fire or explosion.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | User charging of nitrogen gas into an accumulator
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  • When charging nitrogen gas into an accumulator, although it is not regulated by law in Japan, personnel handling the gas should receive proper training on how to handle high-pressure gas and be careful not to put any third party in danger. In addition, please use a suitable charging assembly for the accumulator you use.

     

 

4. Handling the charging assembly

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Charging assembly
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  • Charging assembly should be removed from the accumulator except when performing pressurization, pressurization adjustment or pressure checks. Permanently attaching it to the accumulator will result in gas leakage or damage to the attached pressure gauge.

     

 

5.Operation (use) of accumulators

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Risk of suffering damage due to an accumulator bursting etc.
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  • The accumulator should be used at a pressure not exceeding its max working pressure (design pressure). Exerting excessive pressure on it will result in a risk of suffering damage due to the accumulator bursting etc.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Problems such as the bladder rubber sticking to the inner surface of the shell
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  • Note that if you keep a bladder type accumulator charged gases without liquid pressure for a long time (two or more weeks), the bladder rubber will stick to inner wall of the shell.

     

 

6. Maintenance of accumulators

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Charged gas pressure in the accumulator
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  • Please check and adjust the charged gas pressure immediately after pressurization, one week after and then every three months. This is important for protection of the bladder and functional maintenance of the accumulator. When measuring gas pressure, make sure that the pressure in the hydraulic line is equal to atmospheric pressure.

     

 

    

7. Disassembly/assembly/disposal of the accumulator

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Disassembling the accumulator
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  • Before disassembling the accumulator, completely decompress the internal pressure in hydraulic line to atmospheric pressure, release gas from the accumulator and make it equal to atmospheric pressure. If excessive internal pressure is remaining in the line, the gas will blow out during disassembly, which may result in accident.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | When releasing nitrogen gas
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  • When releasing nitrogen gas, be sure to maintain sufficient ventilation. Otherwise, there is a risk of suffering injury due to lack of oxygen. In addition, check the flow direction of the gas to be released, confirm that personnel and movable objects are not present in the direction, and then release the gas. Otherwise, there is a risk of suffering damage due to the strong force of the released gas.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Checking each part before reassembling the accumulator
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  • Before reassembling the accumulator, make sure that each part is free of abnormal corrosion, damage, deformation, etc. Using abnormal parts without modification will result in a risk of suffering damage due to accumulator bursting etc.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Reassembling the bladder for the twin open series (T series) bladder type accumulator without its top
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  • When reassembling the bladder of the twin open series (T series) from the gas side, completely drain fluid remaining inside accumulator shell. If the fluid remains, buoyancy will cause abnormal deformation of the bladder, thus resulting in damage to the bladder.

     

  • Accumulator manufacturer -- Nakamura Koki Co., Ltd. | Disposal of the accumulator
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  • When disposing of an accumulator, make the liquid and gas pressures equal to atmospheric pressure, disassemble it so as not be reused. After that, properly dispose of it as industrial waste.

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