One method to address this problem of pressure fluctuation is to include an accumulator . (This is also known as an attenuator since its purpose is to reduce or attenuate the variation in maximum to minimum pressure values. This is akin to the attenuation of a waveform as the energy is dissipated over time and hence the amplitude of the vibration decreases).
The attenuator stores a volume of water at an elevated pressure which it will release into the system as a decrease in pump pressure is sensed. This then reduces the variations in system pressure. The size of the attenuator tank must be correlated to the pump to insure successful operation.
An alternate method to reduce variation in pressure is to use two single intensifier pistons together so that one has started its compression stroke, before the second has completed its delivery. Thus as one piston stops, the other is already at pressure and continues the delivery.
Direct drive pumps generally are found in lower pressure applications (i.e. 55,000 pounds per square inch and under). Maintenance on the direct drive pump tends to take longer than an intensifier pump. Direct drive pumps can only run more than one cutting head only if all cutting heads are cutting the same part at the same time. With an intensifier pump, you could have cutting heads on multiple machines, cutting different parts, cycling the various cutting heads on and off in any sequence. The intensifier pump will need to only vary its stroke rate accordingly to maintain flow and pressure.
Directional control valves are one of the most fundamental parts in hydraulic machinery. They allow fluid flow into different paths from one or more sources. They usually consist of a spool inside a cylinder which is mechanically or electrically controlled. The movement of the spool restricts or permits the flow, thus it controls the fluid flow.
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