This SAE Aerospace Recommended Practice (ARP) is a guide for defining the requirements for aerospace piston hydraulic accumulators@ including details pertinent to the design@ fabrication@ performance and testing of the accumulator. This type of accumulator contains a piston which separates pressurized gas and fluid. Field of Application The accumulator is intended for use in commerical and military aircraft hydraulic systems with rated pressures up to 5000 psi (34 474 kPa) and operating fluid temperatures as follows: Phosphate ester based fluid systems: -40 to 225 ??(-40 to 107 ?? Hydrocarbon based fluid systems: -65 to 275 ??(-54 to 135 ??