Doosan DX60R Shop Manual page 471

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 precharge 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
precharge 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 precharge pressure and
hydraulic system oil pressure achieve a rough balance. In
this state a minimal amount of oil is stored in the
accumulator.
Accumulator SP000028
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