Liquid separator type ASL and transfer type AST

Bladder accumulators’ type ASL and AST consist of a seamless cylindri- cal pressure vessel made of high-tensile steel.
The accumulators are subdivided into a gas and fluid side by an elastic bladder mounted in the interior of the vessel.
In the ASL type, the liquid is also inside the bladder.
The transfer accumulator AST type is designed especially for connecting to nitrogen cylinders. A diffuser rod prevents damage to the bladder when the accumulator works.
Nitrogen cylinders used as back-ups increase the gas volume in the accumulator. This means that smaller accumulators can be used for the same gas volume and costs can be reduced.
When the fluid is pressed into the accumulator, the gas in the bladder is compressed and hence the pressure increased. The gas volume reduces and on the fluid side, the fluid can flow into the accumulator. As soon as the pressure on the fluid side falls below the gas pressure, the accumu- lator is emptied.
Oil valve is provided in the oil port of the bladder-type accumulator and closes when the pressure on the gas side is higher than the one on the fluid side. This prevents draining of the bladder into the oil channel and thus the bladder from being destroyed.
When the minimum operating pressure is reached, a small oil volume is to be maintained between the bladder and the fluid volume (approx. 10% of the nominal capacity of the hydraulic accumulator), in order that the bladder does not hit the valve during every expansion process.
The gas valve body of ASL type accumulator is complete with anti-ex- trusion in addition to the rubber washer and locknut.
The gas valve body of AST type accumulator is complete with diffuser rod in addition to the rubber washer and locknut.
These parts can be replaced separately.
The nameplate shows the technical data and features of the hydraulic accumulator.