EFC series for regulating the flow volume of liquids and gases. The position of the precision throttle, which is connected directly to a linear motor, determines the flow rate.
In conjunction with the proven ELSA push-in connectors made from PPSU, this valve is also used in the food industries.valve is also used in the food industries.
The control electronics integrated in the valve housing allow the setting of the motor via an analog voltage signal, whereby the flow rate can be adjusted almost continuously.
A set position can also be maintained unpowered due to the stepper motor technology.
What is an Electronic Flow Control Valve?
Electronic flow control valve is a device that is able to control the flow rate of fluid (liquid and gas) with electronic signal. Ideally, the output flow rate is linearly proportional to input signal.
There are different types of working principle, and in this article we will be introducing you the needle valve type driven by a stepper motor powered linear actuator. We will firstly introduce you what type of electronic flow control valve we offer, followed by the working principle and with what is the main advantage of KaoLu’s electronic flow control valve, and then conclude with what you should think about before purchasing an electronic flow control valve.
What type of Electronic Flow Control Valve does KaoLu offer?
KaoLu offers 4 types of electronic flow control valve . One advantage is that it can control both gas and liquid. Please click on the photo link below for further information
- FC20 : Flow rate up to 45 L/min of nitrogen gas @ 6 bar or
750 mL/min of water @ 6 bar
- FC120: Flow rate up to 200 L/min of nitrogen gas @ 6 bar or
3.5 L/min of water @ 6 bar
- FC300: Flow rate up to 450 L/min of nitrogen gas @ 6 bar or
8 L/min of water @ 6 bar
- FC1000: Flow rate up to 650 L/min of nitrogen gas @ 5 bar or
12 L/min of water @ 5 bar
All four types comes with an equivalent control driver to power up and control. The controller accepts either analogue (0-10V or 4-20mA) or digital RS485 modbus signal. We also provide an option for encoder which ensures that the stepper motor reaches target position. There is also an option for customized solution such as having a stainless steel body and wet material or 0-10V corresponds to 0-200 L/min of gas. As our business partners, we even offer the option to calibrate torque and speed of the moving needle and control range. There is a great flexibility of what our customer could achieve with our electronic flow control valve, which helps customers to solve difficult and unique issues.
Please refer to our youtube channel for some of the interesting applications:
What is working principle of an Electronic Flow Control Valve?
There are different types of electronic flow control valve. Here we will be explaining the type that utilizes a linear stepper motor actuator and needle valve.
Firstly, what is a stepper motor?
Stepper motors are brushless DC motors that rotate in steps set by a driver. The steps are determined by step angle and lead screw and controlling electronics. The driver provides electric current through electromagnets that are arranged in a ring as part of the stator assembly (the stationary portion of the motor). Due to the mechanical design of stepper motor, the mechanical and electrical delays are minimized, which is often a problem with other types of motors. With a stepper motor, the moving accuracy, resolution, and responsiveness is a great advantage over others. Stepper motor has been widely used in automation, motion system, and 3D printers.
Next, what is a stepper motor linear actuator?
A stepper motor can have a threaded shaft attached to its rotating core which can then be used to push or pull a nut (needle valve) placed upon it, moving it axially. The pitch of the thread controls what the resolution of the flow control valve is, this is also dictated by the step angle of the used stepper motor (full, half, quarter, etc.). Like most linear motion systems, a stepper linear actuator is sensitive to backlash, which is defined as the maximum distance or angle through which any part mechanical part may be moved in one direction without applying resistive force or motion to the next part. Having clearance between threads results in a dead zone when the direction of travel is changed. When reversing direction, there will be no movement in the linear actuator until the clearance between threads is removed (the threads make contact again). For this reason, it is recommended that the threads have as tight a tolerance as possible. Mechanical design of stepper motor driven actuation system is imperative to the performance of the valve.
Next, what is a stepper motor driven electronic flow control valve?
Here a stepper motor is used to control the distance between the needle and valve seat. The performance parameters of an electronic flow control valve, such as resolution, accuracy, and repeatability are determined by how well the position of the needles is adjusted. Other parameters such as velocity, torque, operating pressure is mainly determined by the characteristics of the stepper motor.
So, what is the advantage of KaoLu’s electronic flow control valve?
Our parameters tells all the story. With FC series electronic flow control, we are able to withstand 7 bar of perpendicular operating pressure, with a resolution as high as 20 mL/min of air, repeatability of 0.1% F.S, and 0.1% of linearity. This is due to the motor we used, the extremely low tolerance of mechanical parts, the fine thread needle we used which is extremely difficult to reproduce by others, and the control system we designed.
What should you consider when purchasing an electronic flow control valve?
You should consider 3 main factors ( we called CPR)
- Compatibility: Medium, flow range, compatibility with the valve material, and operating pressure
- Performance: Resolution, starting flow point, and linearity
- Control system
It is important to understand whether the media you used falls into the flow range of the operating valve. As each media has different density so the flow range would be different from the nominal flow range. Next is whether the media used is compatible with the wet material and whether you would also need the body to be special material. The operating pressure is another caveat, where if you simply needs flow control, sometimes it would not be a very important factor.
Next is the performance, with some applications that needs fine control and adjustment between steps, such as laser cutting, the resolution dictated by the control logic and motor performance plays an important role here. Furthermore, as the motion system requires to overcome initial inertia, the start flow point is should be considered.
Then comes the control system where the you should check what type of control system do suppliers offer? Here we provide an external driver that has a cable connected to the control valve. The great advantage that we offer is that should you want to operate the valve from distant away from the site, we offer RS485 modbus where you could control the valve up to half a mile away from the valve.
We hope you have enjoyed reading the article, understand about stepper motor driver electronic flow control valve, understand about our products, and finally help you with selecting the right valve.
Please remember to visit our product page (even if it is not the right product for you :)