A flow switch is an instrument used to control the flow of a medium (gas, liquid, oil) flowing through a pipeline. It is used in many areas: HVAC, fire protection systems, industrial automation, food and beverage, pharmaceutical and medical, etc. Read More about Flow Switch.
If you need to buy or replace a flow switch, please refer to our flow switches. Sino-Inst has a complete range of products with various functions.
However, it occasionally has some problems. Such as the indicator light is not on, the indicator light keeps flashing, etc. Based on Sino-Inst’s many years of instrument measurement experience. This article will introduce some related issues of flow switch troubleshooting. I hope it can help you.
First, the structure of the flow switch is introduced. Because only after understanding the structure can we better u
nderstand how to solve the problem of the flow switch.
Flow Switch Structure
The flow switch is mainly composed of the following structures:
Probe: placed in the fluid, the fluid flow causes it to move or rotate, and send a signal to the sensor.
Sensor:
Flow switches with different working principles have different sensors. Flow switches mainly include: thermal sensors, baffle sensors, piston sensors, turbine sensors, etc.
Transmitter: The transmitter receives and processes the sensor signal, compares it with the preset value, and outputs a control signal.
Other components:
- Casing: protects the internal components, usually corrosion-resistant and pressure-resistant.
- Flow hole: the channel through which the fluid passes, where the switch is installed.
- Float: moves with the flow rate and reflects the flow rate.
- Control unit: receives signals, compares with preset values, and controls operations.
- Connection line: connects various components, transmits signals and electricity.
- Seal: prevents liquid leakage.
- Bracket: fixes the switch on the pipeline.
- Regulating valve: adjusts fluid speed and flow.
- Display/indicator: displays flow rate, alarm information, etc.
These components work together to monitor and control fluid flow.
When these components have problems, the flow switch will fail. Below, I will introduce how to calibrate a flow switch.
Flow Switch Calibration
The calibration method of the flow switch mainly includes the following steps:
1. Turn on the power: connect the flow switch to a 24V DC power supply.
2. Parameter setting: set the relevant parameters of the flow switch according to the fluid characteristics and application requirements, such as measurement range, sensitivity, alarm value, etc.
3. Use calibration equipment: After the parameters are set, the flow switch needs to be calibrated using a standard flow meter and calibration equipment.
4. Stepwise adjustment: During the test, gradually adjust the flow switch parameters such as sensitivity and threshold, and observe the response of the flow switch until the best measurement and control effect is achieved.
5. Inspection and verification: After the calibration is completed, perform a flow test. Verify whether the flow switch can accurately reflect the actual flow value. At the same time, check that the setting value of the flow switch is not lower than the factory setting value. By pressing the main lever several times, check whether the switch has a “click” sound when the main lever returns. If it is found that there is no “click”, the adjustment screw should be turned clockwise until there is a “click” sound when the lever returns.
During the entire calibration process, the following points need to be noted:
- Follow the instructions: When setting parameters and performing calibration, you should carefully read the product manual to understand the specific steps and precautions.
- Avoid arbitrary changes: Do not arbitrarily change the parameters that have been set to avoid affecting the accuracy of the measurement data.
How do You Test a Flow Switch?
When the flow meter does not work properly, how should we solve this problem? Here is the solution.
- Check the appearance: Check whether the shell is damaged, deformed, corroded, and whether the connection parts are loose or leaking. If the shell is found to be damaged, it may affect its protective performance and needs to be replaced in time. Loose connection parts may cause unstable signals or fluid leakage, and should be tightened in time.
- Check the operating status: Pay attention to the working status indicator of the flow switch. Under normal circumstances, the indicator light will have a corresponding display according to its different working modes. For example, when the flow is normal, the green light is always on. When the flow is abnormal, the red light is on. If the indicator light is abnormal, such as not on or flashing irregularly, it may indicate that the flow switch is faulty.
- Check the signal: Check whether the signal output by the flow switch is normal. You can check whether the signal sent by the flow switch can be accurately received by connecting to the relevant monitoring equipment or control system. Whether the signal is stable and whether there is any interruption or false alarm. If the signal is abnormal, it may be an electrical connection problem or a fault in the signal processing circuit inside the flow switch.
The inspection of the water flow switch is similar to the inspection of the flow switch.
How do you check a Water Flow Meter?
1. The water flow switch cannot be activated or does not respond:
– Check whether the power supply is normal and make sure that the switch wiring is connected correctly.
– Check whether the switch is blocked or damaged, clean or replace the switch.
– Check whether the control circuit and relay of the switch are working properly, repair or replace the faulty parts.
2. The water flow switch misreports or mistriggers:
– Check the sensitivity setting of the switch and adjust it according to actual needs.
– Check whether there is abnormal water flow or vibration around the switch, which may cause false alarms.
– Check whether the switch is subject to external interference or electromagnetic interference, and ensure that the surrounding environment is stable.
3. The water flow switch cannot accurately measure the flow rate or flow:
– Check whether the switch is correctly positioned and installed to ensure that the water flow can fully contact the switch.
– Check whether the sensor of the switch is clean, clean the sensor surface to eliminate dirt or sediment.
– Check the calibration and verification of the switch, adjust or recalibrate as needed.
4. The flow switch has water leakage or sealing problems:
– Check whether the seals and connections of the switch are intact.
– Check whether the pipes and valves around the switch are damaged or loose.
– Use a higher quality flow switch or add additional sealing measures.
For more complex faults or repairs that require professional knowledge. You can consult Sino-Inst for accurate fault diagnosis and solutions.
When the problem with the flow switch is found, how do we solve the flow switch failure? Here are the solutions.
Flow Switch Troubleshooting
When the flow switch fails, the following methods can be used to deal with it:
If the valve is stuck or blocked, the valve needs to be cleaned or replaced.
1. The flow indicator light is not on.
- The flow rate does not reach the set value
- The probe is dirty
- The indicator light is mechanically damaged
- The probe is mechanically damaged
- The power supply is abnormal
- The circuit is damaged.
We should increase the flow rate or lower the set value and clean the dirt on the probe.
2. The indicator lights are all displayed normally, but the output is wrong.
- Incorrect wiring
- The cable is disconnected
- The relay is damaged.
- The plug is not connected,
- The cable is disconnected
3. The potentiometer adjustment does not respond:
- The adjustment tool is improper
- The potentiometer is mechanically damaged
4. The power indicator light is not on:
- The wiring is incorrect
- The power module is damaged, etc.
When the above methods fail to solve the sensor failure, you need to contact a professional technician to troubleshoot the problem for you. You can also contact us. We, Sino-Inst, have rich experience in instrument measurement. We can solve the problem for you.
How to Prevent Flow Switch Failure?
In order to reduce the frequency of flow switch failure, the following preventive measures can be taken:
1. Regularly check the operation of the flow switch.
2. Regularly maintain and maintain the flow switch.
3. Develop corresponding emergency plans for common problems of flow switches.
4. Cleaning: Clean the flow switch regularly (usually every 3-6 months).
5. Calibration: Calibrate the flow switch regularly (usually once a year) according to the usage and accuracy requirements.
6. Electrical connection inspection: Regularly check the electrical connection part of the flow switch, including wiring terminals, cables, etc.
7. Component inspection: Check the internal components of the flow switch, such as springs, valve cores, seals, etc., to see if there are signs of wear, deformation, aging, etc.
Please note: During daily maintenance, we should be careful not to damage electronic components. We cannot affect the daily working status of the sensor.
Sino-Inst is your best partner for process control. We have extremely rich experience and professional technicians. We support customization and OEM. Please choose us with confidence. We can provide you with the most suitable measurement solution. If necessary, please contact us.
