What Are Control Valves?
Control valves are critical components in industrial control systems as they control the flow of fluids such as gas, steam, and liquids by regulating the opening area. The control system defines the operating parameters of the final control elements of the system, and it is imperative that they be reliable devices that regulate fluid flows in a system. The placement of control valves must be deliberate since it must be effective, non-essential, and secure. There is a wide variety of valve types and generally, ball valves, gate valves, and butterfly valves are the most commonly used types of control valves for specific purposes; high pressure steam, low pressure water, etc. The actuator utilized, whether pneumatic, electric or hydraulic, etc., insights or variables such as differential pressure and/or flow rate will all act on the valves. Of these, automatic control valves，particularly electric control valves find substantial application owing to their degree of accuracy and present system compatibility.
Why are electrically actuated control valves more popular?
Safe and high precision electrically actuated control valves that are easier to integrate with computerized control systems are now widely used. They control the valve position by opening it to a predetermined angle with the actuator being driven by an electrical signal. For example, in the case of a chemical plant, the use of electric control valves can increase the general accuracy in the processes by an estimation of about 20% compared to conventional methods.
Maintaining pressure like in pneumatic actuators is done by the sufficient amount of air supply that a pneumatic system needs; however, electric systems do not necessitate such a massive air supply as they offer consistent control signals. Electric valves are also fast in responding to commands, which is an advantage in systems that require rapid adjustments.
Moreover, fail-open features with low pressures mean high electrical currents are not required to keep the valves in the closed position, which reduces the chances of blockage during power failure. This benefit is further enhanced by the use of spring pressure to maintain the valve position. The rotary motion generated by the actuator, as well as components like the piston, ensures quick and precise response. These properties render the electrically actuated valve best suited for the pharmaceutical and food industries where a high level of precision and reliability is required. The more we advance in our consideration of automatic control valves, the more it becomes clear that their positioning is critical in the process of attaining optimal safety and performance.
Why Control Valve Positioning Matters
Control valve positioning is crucial for energy saving as well as system management. At VINCER, we understand the importance of positioning of the valve clearly. While it might sound complex, it is necessary to clear the air by providing a few examples from day to day life along with some figures.
Control valve positioning affect energy efficiency in a system
Positioning a control valve has a big impact on energy use within a system. For example, A Unit of the United States Department of Energy estimated that energy use can be cut by over 20% through optimal use of valves. The cause of this is that precise control always interfaces with unnecessary pressure that would otherwise be used to pump fluids Hence, excessive energy is consumed. For example, steam flow levels could be maintained by 15% higher energy consumption than required if a control valve is incorrectly set. Imagine a large manufacturing facility that saved approximately $50,000 annually in energy costs by optimizing control valve settings—this is the potential impact of correct valve positioning.
Control valve positioning impact system pressure and flow
Beyond energy, valve positioning directly affects system pressure and fluid flow. For example, in a water supply network, incorrect valve positioning can cause flow and pressure fluctuations, leading to potential system failures. Imagine a valve accidentally remaining open position when it should in a closed position; this could cause a 10% increase in pressure drop, affecting the entire network’s balance.
Moreover, using the correct valve sizing and valve type in specific conditions simplifies control and optimizes functionality. For example, globe valves are excellent for precise control in fluctuating flow conditions. They can handle differential pressures effectively, stabilizing the system. On the other hand, ball valves are designed for quick shut-off, but they need to be accurately placed to prevent disruption of the system.
Common Mistakes in Control Valve Positioning
From the control valve perspective, sloppy installation of the control valve has become a familiar issue I have come across being a professional in this field which compromises system operational efficiency and system safety as well.
- First and foremost, thrusting valve of incorrect type or size is very common with installers. The effect of this is quite disastrous as simply due to the imbalance between the system and valve size the very flow dynamics of the system will suffer. For instance an oversized valve will create instability in control yet a smaller valve will reach its peak flow rate eventually and quite unproductively so lead to system inefficiencies.
- Another big error is not paying attention to the condition of the valve stem and the plug. These are very important for precise valve positioning as any of the above mentioned components when worn out or out of alignment can induce inaccuracies. Such issues can lead to a static pressure drop and potential leaks, which compromise system reliability. Routine inspections and maintenance of these components can assure that the valve functions as intended throughout its service life.
- Focusing on the value of a valve in its closed position is also very wrong. The balance also has to be on different fluid loads that will be experienced as well as the system dynamics. Sole reliance on static data will bring about such inefficiencies as heating balances or leakages. In preparing control valves, consider both dynamic and steady-state conditions, minimizing the risk of improper closing of automatic control valves, to improve the performance of these valves when in use.
In doing so, these studies help enhance the efficiency as well as the overall performance of the control valve systems.
Electric Control Valves: Enhancing System Safety
Vincer, as an electric control valve manufacturer, is aware that electric control valves are very vital to the system’s safety of the entire unit. Our valves are equipped with unparalleled precision that guarantees ideal positioning of control systems at all times. Notably, our fail-open configuration design is very crucial in maintaining most essential operations even in the absence of power. Such a design feature is quite important to precision systems that require non-stop flow. Such systems are common in chemical plants where factors such as an unexpected power failure may create a situation of excessive pressure behind a flow seal that if not tended, may be detrimental to the plant. Also, when our valves are incorporated with electronic control systems, we provide closed-loop control, which allows to adjust the valve in case of inaccuracies, and assists in rapid reactions if ever required.
Founded in 2010, Vincer has completed over 800 projects and holds more than 30 patents, underscoring our dedication to innovation and reliability. According to feedback from a large refinery customer, after using our valves, safety incidents were reduced by 15% within one year. Furthermore, By employing a hybrid control system that includes pneumatic actuators as a backup, we provide an extra layer of protection for our clients’ critical systems. Our clients don’t just reach industry safety standards with our valves but greatly exceed it. Moreover, another client, a water treatment facility, placed Vincer valves and stated a 20% increased operational efficiency as a result of that change. Such a result surely validates expectations our clients have about the quality and reliability of our products and services.
Maintenance Tips for Ensuring Control Valve Positioning
- Regular Inspection and Lubrication
In controlling properly position of control valves, it is expected that there will be a routine inspection of the valve body, stem, and gland so as to prevent frictional wear and leak. Rotating parts must be adequately lubricated as to alleviate some friction which may hamper effectiveness. Scheduling actuator response check during inspection of the system may also assist in dealing with major operational snags.
- Routine Testing and Tuning
It is advisable for someone to regularly check the valve and more so the fail-open option for it to be functional when it is really required. It is important to wash a diaphragm off the dust, tuners can do this during controller parameters adjustment. Regularly checking spring pressure setting and valve positioners allows for running valves in the proper way which enhances system durability. Routine maintenance practices like these are vital for sustaining optimal control valve performance over time.
Selecting the Right Control Valve Position for Different Systems:
In various systems, identifying the control valve optimal position requires careful assumptions of the system requirements and parameters.. Let us take electric control valves as an example to discuss three characteristic system types where the control valves are crucial for system operation and the position of the valve for improved system performance.
|
System Type |
Valve Functionality |
Optimal Positioning |
Key Considerations |
|
Steam Distribution |
Fail-open setup to prevent excessive pressure build-up. |
Placed after pressure-reducing stations. |
Ensures safety by mitigating pressure surges; crucial for systems operating at high temperatures. |
|
Fluid Distribution |
Modulation to maintain balanced flow and pressure. |
Typically mid-range in pipelines. |
Optimizes flow control, reducing wear on piping and enhancing lifespan; adjustability is essential. |
|
HVAC Systems |
Controls air flow volume and temperature regulation. |
Positioned at duct junction points. |
Critical for energy efficiency; impacts comfort levels and operational costs in large facilities. |
Explanation:
Steam Distribution: It is important that safety issues are attended to in steam systems, thus, it is recommended that a fail open valve which is installed after a pressure reducing stations be implemented to avert hazardous pressure build up. This is important in upholding safety standards in any system that has to do with high pressure steam and involves careful monitoring of differential pressure.
Fluid Distribution: When it comes to liquid systems, modulating valves are indispensable. These are fitted in the middle of piping systems to regulate fluid flow and stability. By maintaining a consistent flow rate, this method increases the efficiency of the system while minimizing possible erosion of the pipes, hence sustaining the desired performance in the long run. Monitoring liquid level and differential pressure is essential for optimal valve positioning in these systems.
HVAC Systems: Control valves in HVAC are installed at duct junctions in order to control air flow and temperature. The position of the control valves is also an important determinant of energy saving and indoor climate control, both of which affect the efficiency of operation. Parameters such as fluid flow are critical for ensuring optimal system performance.
By focusing on the flow of fluids and valve positioning in these systems, assists us in providing sufficient information to our electric control valve clients such that, they are able to make informed decisions with regard to the specific advantages and operational efficiency of the system.
Conclusion: Control Valve Positioning
As a final note, this paper emphasizes that careful observation of a control valve and its environment can lead to better decisions focused on system optimization, improving efficiency and enhancing performance. Adhering to guidelines for proper placement is critical in achieving these objectives.
The next feasible steps are: troubleshooting of the valves on a regular basis, ensuring correct alignment of the valve actuators, and implementing the fail open procedure as a safety measure. The design approach should cater specifically to the needs of individual systems, allowing for improved segmentation of valve positions in response to dynamic pressure changes and fluid flow forces. This strategy maximizes the usefulness of electric control valves, ensuring they fulfill their role as vital elements of modern control systems.
VINCER Company is committed to achieving 100% client satisfaction. If you have any questions or concerns, please do not hesitate to contact us.We would be pleased to work with you in order to achieve the optimal operational conditions for your electric control valves.