Pressure accumulator operation

What is a hydraulic accumulator?

A hydraulic accumulator is a pressure storage reservoir in which an incompressible hydraulic fluid is held under pressure that is applied by an external source of mechanical energy.

What is accumulator flow used for?

They are used to store or absorb hydraulic energy. When storing energy, they receive pressurized hydraulic fluid for later use. Sometimes accumulator flow is added to pump flow to speed up a process. Other times the stored energy is kept in reserve until it is needed and may be independent of pump flow.

How does accumulator pressure work?

An accumulator can provide constant clamping pressure, even while flow is slowly lost to leakage through piston seals or control valve clearances. When accumulator pressure drops to a critical point, a pressure switch will tell the pump to come on for only as long as it takes to refill the accumulator.

How much pressure does a pressure accumulator take?

When the system is turned on, while all control valves are closed, the pump (which is capable of 3,000 psi), will start flowing, and with 1,800 psi at the accumulator, it is the current path of least resistance. The accumulator will take full pump flow until pressure reaches 3,000 psi, where it will bypass over the relief valve.

What is a precharge pressure accumulator?

Its initial gas pressure is called the “precharge pressure.” When the system pressure exceeds the precharge pressure, the nitrogen gas is squeezed, compresses and decreases in volume, letting hydraulic fluid into the accumulator. The accumulator’s fluid volume increases until the system reaches its maximum pressure (P2).

How does a cylinder accumulator work?

The cylinder is closed by a piston on which a series of weights are placed that exert a downward force on the piston and thereby pressurizes the fluid in the cylinder. In contrast to compressed gas and spring accumulators, this type delivers a nearly constant pressure, regardless of the volume of fluid in the cylinder, until it is empty.