SBO Diaphragm Accumulators

Key Features

  • Compact design
  • Low weight
  • Flexible mounting positions
  • Extremely quick shock response
  • Low cost
  • Low lubricity fluids, like water


  • Agricultural Machinery & Equipment
  • Forestry Equipment
  • Machine Tools
  • Mining Machinery & Equipment
  • Mobile & Construction Equipment
  • Off-Road Equipment

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HYDAC diaphragm accumulators utilize the compressibility of a gas (nitrogen) in storing hydraulic energy. The gas is required because fluids are practically incompressible and thus, can not store energy by themselves. The diaphragm is utilized to separate the gas and fluid sides of the accumulator.
The diaphragm accumulators functions by drawing in fluid from the hydraulic circuit when the pressure increases and thus, compresses the gas. It returns this energy to the circuit as the pressure decreases by the expansion of the gas.
A poppet is incorporated into the diaphragm to prevent its extrusion through the fluid port.

HYDAC manufactures two types of diaphragm accumulators:

  • welded (non-repairable)
  • threaded (repairable)
These have been successfully applied to both industrial and mobile applications in energy storage, maintaining pressure, leakage compensation and vehicle hydraulic systems (e.g. brake  and suspension)  

Diaphraghm Materials

Not all fluids are compatible with every elastomer at all temperatures, therefore, HYDAC offers the following materials:

  • NBR (Standard Nitrile)
  • LT-NBR (Low Temperature Nitrile)
  • ECO 30 (Epichlorohydrin)
  • IIR (Butyl)
  • FPM (Fluorelastomer)
  • others (available upon request)