The flow and pressure control valve is a multifunctional valve mainly used to control the flow and pressure in the pipeline. It can keep the preset flow stable, limit excessive flow, appropriately reduce the upstream high pressure and the downstream flow will not be affected by the upstream pressure change. There are a variety of connection methods and control adjustment methods to choose from.
Flow and pressure
The difference between flow and pressure.
1. Definition differ
• Flow rate refers to the volume of fluid passing through a certain cross section per unit time. For example, in a pipe, the volume of water flowing through it per second is the water flow rate. Pressure mainly describes the flow rate of the fluid.
• Pressure is the force acting perpendicularly on the surface of an object divided by the area of the object. In a fluid, pressure is generated by factors such as the fluid’s own gravity, the kinetic energy of the flow, and external forces. It reflects the intensity of the force exerted by the fluid on the surrounding environment.
2. Units differ
• The units of flow rate are usually m³/s, L/min,etc.
• The units of pressure are Pa, MPa, bar, etc.
3. Physical meanings differ
• Flow rate mainly reflects the amount of fluid passing through in a period of time, focusing on describing the dynamic behavior of the fluid.
• Pressure is more a reflection of the mechanical state of the fluid at a particular location.
Relationship between flow and pressure
Flow and pressure are closely related in hydraulic systems. Flow and pressure affect each other. An increase in flow will cause the system to increase pressure to overcome resistance and load, and an increase in pressure will also increase flow.
At the control level, flow and pressure are closely linked. Hydraulic system design and regulation need to be considered simultaneously. By adjusting the flow control valve, the flow rate can be affected and the pressure change can be indirectly controlled. With the help of the pressure control valve, the pressure can be accurately regulated.
In practical applications, the relationship between flow and pressure is crucial to the performance and stability of the hydraulic system. Insufficient flow may cause pressure drop and affect system operation, while excessive pressure may damage equipment and pipelines.
Selection guide for flow and pressure control valve.
Flow and pressure control valve selection recommendations for various industrial applications:
1. Chemical Industry
In the chemical industry, flow pressure control valve needs to cope with complex chemical medium and strict process requirements. A combination of a control valve and a pressure safety valve or a pressure reducing valve can be selected.
The control valve can accurately control the flow, the pressure safety valve protects the system from over-pressure damage, and the pressure reducing valve maintains the system pressure stable.
2. Petroleum industry
The flow pressure control valve in the petroleum industry must adapt to special medium such as crude oil and refined oil as well as high-pressure environments.
Suitable for use with corrosion-resistant and high-pressure resistant ball valves and pilot-operated pressure control valves. The ball valve can control the flow of petroleum fluid, and the pilot pressure control valve ensures the stability of system pressure and ensure the safety of petroleum production and transportation.
3. Food processing industry
The food processing industry has extremely high requirements for hygiene, and flow pressure control valve must meet strict hygiene standards. It is best to combine a sanitary butterfly valve or diaphragm valve with a pressure control valve that meets sanitary standards. They are easy to clean and do not contaminate food, while the pressure control valve stabilizes the system pressure to ensure the quality and safety of food processing.
What are the advantages and disadvantages of common flow pressure control valve?
1.Ball valve
The ball valve can effectively prevent leakage with its excellent sealing performance and is suitable for occasions with high sealing requirements, such as HANUMAN’s Q941F, Q944F-Q945F and other series.
The ball valve has a small flow resistance, which can reduce pressure loss and improve system efficiency. The switch operation is fast, and it can be fully opened or closed by rotating 90 degrees, which is convenient for rapid flow control. The ball valve has a sturdy structure, high reliability and long service life.
But ball valves have relatively low control accuracy in fine-tuning flow and pressure, and high-performance models are expensive and have complex manufacturing processes. Due to their switching characteristics, the fluid erodes the ball and valve seat more when the opening is small, so they are not suitable for precise flow throttling control.
2.Butterfly valve
The butterfly valve has the characteristics of simple structure, small size and light weight, which makes installation and maintenance very convenient. For example, HANUMAN’s D941X-F, D671X-D641X and other series have the characteristics of fast opening and closing, small operating torque, and rapid response to flow changes.Moreover, compared with high-end control valves, butterfly valves are more economical and affordable.
But the butterfly valve has poor sealing performance under low pressure or large diameter conditions and may leak. The flow resistance is large when the fluid passes through, and the pressure loss is significant especially at partial opening. In addition, due to its structural limitations, butterfly valves are not suitable for high-pressure applications and have limited pressure-bearing capabilities.
3.Gate valve
The gate valve has excellent sealing performance. When the gate is fully closed, the gate and the valve seat are tightly and reliably connected. HAMUMAN’s Z641H series is suitable for harsh working conditions such as high pressure and high temperature. When fully open, the fluid passes smoothly, the flow resistance is small and the pressure loss is extremely small. At the same time, the gate valve has good wear resistance to medium containing solid particles.
But gate valves have the disadvantages of slow opening and closing speed, large volume and high price, especially when the diameter is large due to their structural characteristics. These factors limit their application in occasions that require fast operation, limited space or cost sensitivity.
Performance of flow and pressure control valve in different functions.
In different functional scenarios, the performance of flow and pressure control valve is different.
1. High-precision measurement function.
Flow and pressure control valve is highly precise and can accurately control fluid flow and pressure. For example, in the pharmaceutical industry, when filling medicines, both can be controlled within a very small error range to ensure accurate measurement.
Strong stability, not affected by slight changes in temperature and pressure, stable output. Sensitive response, can be adjusted in time according to measurement needs. Sensitive response, can be adjusted in time according to measurement needs.
2. High-voltage system control function.
The flow and pressure control valve is resistant to high pressure and can withstand huge pressure and accurately control flow and pressure in high-pressure working environments such as oil extraction.
They are highly reliable and can operate stably for a long time in harsh high-pressure environments without prone to failure. They can handle large flows to ensure efficient operation of the system.
They can also accurately adjust the pressure to keep the system within a safe pressure range. They respond quickly to pressure changes and can quickly release pressure when over-pressure occurs, providing safety protection.
Troubleshooting manual for flow pressure control valve:
1. Flow pressure control valve common troubleshooting steps.
- Observe abnormal performance, such as noise, vibration, leakage, etc.
- Check whether the meter reading is normal.
- Check the status of power supply and control system.
- Check the pipeline connection and sealing.
- Check whether the valve core moves smoothly.
2. Flow pressure control valve common failure solutions.
- Leakage: Replace seals and tighten connections.
- Valve core stuck: Clean the valve core and remove impurities.
- Unstable pressure and flow: Adjust parameters and check sensors.
- Electrical failure: Repair power supply and control circuits.
3. Flow pressure control valve maintenance and repair techniques.
- Clean regularly.
- Check seals.
- Lubricate moving parts.
- Calibrate instruments.
4. Prevent future problems.
- Correctly select the model of flow pressure control valve to install.
- Regular maintenance inspection.
- Train operators.
- Pay attention to changes in the working conditions of the flow pressure control valve and make timely adjustments.
Best practices for installation and commissioning of flow pressure control valve.
Installation process of flow pressure control valve:
1. Pipeline Preparation
• Clean the pipeline: Before installing the flow pressure control valve, make sure that the inside of the pipeline is clean and free of debris, rust, welding slag, etc. Cleaning can be done by blowing, flushing, etc.
• Check pipe size: Confirm that the pipe’s diameter, wall thickness and other dimensions match the connection size of the control size.
• Cutting and beveling: Cut the pipes as needed and perform beveling to ensure welding quality.
• Mounting bracket: Install suitable brackets on the pipeline to support the weight of the control valve and prevent pipeline vibration.
2. Valve positioning
• Determine the installation location: Determine the installation location of the control valve based on the process flow and operating requirements. Generally, it should be selected in a place that is convenient for operation and maintenance, and the direction and layout of the pipeline should also be considered.
• Consider the flow direction: Install the control valve correctly according to the flow direction arrow marked on the control valve to ensure that the flow direction of the fluid is consistent with the design flow direction of the valve.
• Distance from other equipment: A certain distance should be maintained between the control valve and other equipment (such as pumps, filters, etc.) to facilitate installation, operation and maintenance.
3. Valve fixing
• Flange connection: For flange-connected control valves, the valve should be securely connected to the pipe flange using appropriate bolts and nuts. When tightening the bolts, they should be tightened step by step in a diagonal order to ensure uniform force on the flange connection.
• Welded connections: Welding connection: For control valves with welding connection, appropriate welding process and materials should be used for welding. During the welding process, attention should be paid to controlling the welding temperature and welding speed to prevent the valve from overheating and deformation or damage to the internal seals.
• Threaded connection: For control valves with threaded connections, use a suitable pipe thread sealant or sealing tape for sealing and tighten the valve with a wrench.
Precautions in commissioning flow pressure control valve.
1. Stress test:
• Before pressurizing the pipeline system, the valves must be closed to ensure safe testing.
• Gradually increase the pressure in the piping system and observe and record the pressure gauge reading.
• Check the valves and their connections for leaks, if any, deal with them promptly.
• Ensure that the valve can work normally and seal well when subjected to the design pressure.
2. Leakage check:
• Use soapy water or other leak detection tools to check the valve and its joints for leaks.
• Pay special attention to check the flange joints, gaskets and valves for leaks.
• If leaks are found, shut down the machine and repair the leaks immediately.
3. Performance verification:
• Verify whether the valve opens and closes flexibly and reliably.
• Check whether the valve can meet the design requirements when adjusting flow and pressure.
• If necessary, flow test and pressure adjustment test can be carried out to verify whether the performance parameters of the valve meet the standards.
IIoT connectivity with automation and digital control.
Integrating flow pressure control valve with the IIoT platform is the key to achieving intelligent production. Select compatible sensors and actuators, accurately measure flow and pressure, and configure the communication protocol access platform.
Automatic and digital control valves not only respond quickly, but also greatly improve operational efficiency and accuracy through remote monitoring and automatic adjustment.
The data analysis capabilities of the IIoT platform help companies optimize control strategies, achieve predictive maintenance, reduce downtime, and improve overall competitiveness.
