In servo control systems, the variable-displacement or servo pump performs the same basic function as the control valve. However, the servo pump generates the controlled…
Author: Jack
The principle of converting pressure into kinetic energy and then reconverting this energy into a controlled pressure can be utilized as a control means. The…
The four-way flapper-nozzle valve has two identical hydraulic circuits, one supplies flow and pressure to one side of an actuator, the other circuit supplies the…
The flapper-nozzle valve has certain mechanical design advantages mainly the simpler construction and the feature of no close-clearance sliding parts as compared to the spool-type…
The two-way valve is merely a throttling valve having one variable-area orifice. When used in conjunction with a constant-flow source, the two-way valve can be…
The three-way control valve uses only one control pressure line to the actuator with the normal pressure supply line and a drain or return line.…
When a valve is designed to use a constant-flow source of fluid, the valve does not have its cont.rolling edges covering their corresponding port edges.…
There are many ways of compensating for the reaction forces in spool type valves. In general most of these methods do not actually change the…
Figure 1.11 illustrates the valve reaction forces for an uncompensated four-way valve. It can be noticed that the forces become very large for the higher…
In addition to the flow which the valve supplies to the piston, there is also a small amount of leakage flow within the valve itself.…