The main purpose of an electronic control valve in a hydraulic system is to regulate speed and flow rate. All the devices discussed here help you to control the speed of an actuator by regulating the flow rate. Control flow rate is also used to determine the rate of energy transfer at any given pressure in the system. There are two related in that the actuator force multiplied by the distance via which it carries (stroke) equals the work done on the load.
The energy transferred must be also equal to the work done which is covered by the system. Actuator speed resolves the rate of energy transfer (i.e., horsepower), and speed is thus a function of flow rate. While on the other hand, directional control does not deal primarily with energy control but instead of directing the energy transfer system to the accurate place in the system at the proper time.
The directional liquid flow control valve can be assumed as fluid switches that make the expected”contacts.” That is, they direct the high-energy input stream to the actuator inlet and deliver a return path for the lower-energy oil. An electronic control valve is of slight significance to maintain the energy transfer of the system through pressure and flow controls if the flow stream does not arrive at the right place at the right time. Therefore, a secondary process of directional control device energy is defined as the timing of cycle circumstances. Since fluid flow usually can be throttled in directional-control valves, some measure of flow rate or pressure control can also be performed with them.
Components of flow control needle valve
An automatic electronic control valve consists of three main parts. These are:
Valve actuator – which moves the valve’s modulating factors, such as ball or butterfly.
Valve positioner – which provides the valve has reached the expected degree of opening. This overcomes the problems of friction and wear.
Valve body – in which the modulating element, a plug, globe, ball, or butterfly, is contained.
Different types of flow measurement
Controlling the electronic control valve of a fluid-power system does not necessarily mean regulating volume per unit of time from a valve. The digital flow control valve can be identified in three different ways, so it is important to be familiar with how flow is to be specified or measured:
Volumetric flow rate, Qv,
It is expressed in units of in.3/sec or min – or cc/sec or cc/min in SI metric measure which is specifically used to estimate the linear speeds of piston rods or rotational speeds of motor shafts.
Weight flow rate, Qw,
It is generally expressed in units of lb/sec or lb/min, which is specifically used to estimate the power using English units of measure.
Mass flow rate, Qg,
The value of electronic flow control is represented in units of slugs/sec or slugs/min for English measure or kg/sec or kg/min in SI metric measure which is specified and is used to calculate inertia forces during periods of acceleration and deceleration through the system.