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
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
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
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
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
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
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
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
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
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