Category Archives for Fluid Flow

Hydraulic Meter-out Circuit

In the meter-out operation shown in Figure 6.39, the direction of the flow through the circuit is simply changed as can be made out from the diagram. It is the opposite of a meter-in operation as this change in direction … Continue reading

06. January 2011 by and
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Hydraulic Meter-in Circuit

Meter-in is a method by which a flow control valve is placed in a hydraulic circuit in such a manner that there is a restriction in the amount of fluid flowing to the actuator. Figure 6.38(a) shows a meter-in operation … Continue reading

06. January 2011 by and
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Pressure-compensated Flow Control Valves

Figure 6.35 illustrates the operation of a pressure-compensated valve. The design incorporates a hydrostat which maintains a constant 1.4kg/cm2 (20 psi) pressure differential across the throttle which is an orifice, whose area can be adjusted by an external knob setting. … Continue reading

06. January 2011 by and
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Hydraulic Non-pressure-compensated Valve

This type of valve is used where the system pressures are relatively constant and the motoring speeds are not too critical. They work on the principle that the flow through an orifice will be constant if the pressure drop remains … Continue reading

06. January 2011 by and
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Hydraulic Ball Valves

This is another type of flow control valve shown in Figure 6.31. It is made up of a ball with a through hole which is rotated inside a machined seat. The manner in which flow control is exercised can be … Continue reading

06. January 2011 by and
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Hydraulic Butterfly Valve

This is another type of flow control valve. It consists of a large disk which is rotated inside a pipe, the restriction in flow being determined by the angle. Figure 6.30 shows a simple design of a butterfly valve. The … Continue reading

06. January 2011 by and
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Hydraulic Globe Valve

This is the simplest form of a flow control valve. The globe valve gets its name from the disk element ‘globe’ that presses against the valve seat to close the valve. A simplified view of a globe valve has been … Continue reading

06. January 2011 by and
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Hydraulic Flow Control Valves

A flow control valve is a device used for adjusting or manipulating the flow rate of a liquid or a gas in a pipeline. The valve contains a flow passage or a port whose flow area can be varied. The … Continue reading

06. January 2011 by and
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Rotary Four-Way Directional Control Valves

Although most direction control valves are of spool type design, other types are also used. One such design is the rotary four-way valve, which consists of a rotor closely fitted in the valve body. The passages in the rotor connect … Continue reading

22. December 2010 by and
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Hydraulic Flow Control Valves

Flow control valves are used in constant-flow (fixed displacement pump) circuits to control actuator speed. The simplest type of flow control valve is a needle valve. Another name for a needle valve is a non-pressure-compensated flow control valve. Turning the … Continue reading

27. January 2010 by and
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