10. ACCUMULATOR 10. ACCUMULATOR The accumulator is installed at the safety valve. When the boom is left the raised position, and the control levers are operated with the engine stopped the pressure of the compressed nitrogen gas inside the accumulator sends pilot pressure to the control valve to actuate it and allow the boom and bucket to come down under their own weight. 1 2 3 Type of gas Nitrogen gas (N 2 ) 1 Diaphragm 2 Steel pressure vessel 3 Closure button 7803AWE56 6-39 Volume of gas 0.75˶(0.2 U.S.gal) Charging pressure of gas 16 kg/cm2 (228 psi) Max actuating pressure 128 kg/m2 (1820 psi)