S0703010K Page 4 Accumulator NOTE: Pre-charge pressure is referred to as the "P1" pressure. The accumulator manufacturer’s "P1" rated pressure should be stamped or marked on the accumulator’s rating plate. Annual checks of actual pre-charge pressure should be made by tapping a hydraulic pressure gauge (and 3-way adapter coupling) into the valve on the bottom of the accumulator. When hydraulic fluid is pushed out the lower valve opening by the pressure of the gas charge on the other side of the diaphragm - and there is no counter-pressure from system oil - the valve button on the bottom of the diaphragm eventually seals off the lower oil passage.
Just after the needle on the gauge reaches its highest point (when there is 0 bar (0 psi) resistance from hydraulic system pressure) pressure on the gauge will drop sharply to zero, as the accumulator is completely emptied of oil and the diaphragm button closes. Record the highest gauge reading and compare to the "P1" rated pre-charge pressure on the accumulator manufacturer’s data label. Repeat this test at least once a year to verify proper functioning of the accumulator. 3. As hydraulic system pressure overcomes accumulator pre-charge pressure, the flexible diaphragm begins to retract upward. 4.
When system oil is at highest working pressure and the accumulator fills to maximum reserve capacity, the flexible diaphragm is pushed up into the top of the upper chamber. The highest working pressure is sometimes referred to as the "P3" pressure and can also be referenced on the manufacturer’s data label on the exterior of the accumulator. 5. If system oil pressure begins to fall off or is momentarily checked or interrupted, the energy stored on the other side of the diaphragm, in the form of compressed gas, pushes oil back out of the lower chamber, maintaining oil pressure of the circuit. 6.
With minimal system pressure, an equilibrium point may be reached in which accumulator pre-charge pressure and hydraulic system oil pressure achieve a rough balance. In this condition a minimal amount of oil is stored in the accumulator. SPECIFICATIONS Accumulator Model Nitrogen Charge Volume Solar 300LC-V Solar 300LL Solar 340LC-V Solar 420LC-V Solar 470LC-V 10 kg/cm2 (142 psi) 320 cc (19.5 in3)