Control Valve Application Tips

Control Valve Application Tips

Incorrectly applied or sized control valve may have significant ramifications for operation, production, and, most importantly, safety. 

Here is a brief checklist of things to think about:
  1. Control valves are not isolation valves. Don't apply them as such.
  2. Always carefully choose the suitable construction material. Consider the valve components that come into contact with the process medium, such as the valve body, seat, and other "wetted" portions. Consider the control valve operational pressure and temperature exposure. Finally, examine the surrounding environment and any corrosives that may arise and affect the outside of the valve. 
  3. Place the flow sensor upstream of the control valve.  When the flow sensor is downstream of the control valve, it senses a less stable flow stream created by turbulent flow in the valve cavity. 
  4. Consider the degree of control you need and ensure that your valve's design will provide the controllability you require. 
  5. Excessive dead-band leads to hunting and poor control. The change of input signal necessary to induce a change in valve position is dead-band. Dead-band is affected by worn or loosely fitting mechanical linkages or a controller setting. It may also be affected by mechanical sensor tolerances, friction in the valve stems and seats, or an undersized actuator. 
  6. Think about stiction. Stiction is the propensity of valves that have had very little motion or have not moved at all to "stick." It is usually produced by the valves, packing glands, seats, or the pressure applied to the disk. 
  7. Make sure your loop controller is appropriately tuned.  Overshoot, undershoot, and hunting are symptoms of a poorly tuned controller. Check your proportional, integral, and derivative controller settings. Today, employing controllers with powerful, accurate auto-tuning capabilities that have replaced the old-fashioned trial and error loop tuning approach, is relatively simple. 
  8. Avoid oversizing your control valve.  Control valves are usually oversized for the flow loop they control. A tiny change in valve position has a considerable influence on flow. If the control valve is too large, only a fraction of its valve travel occurs, causing the valve to hunt, leading to severe wear. Always size a control valve to allow 70-90 percent of travel. 
  9. Consider the kind of control valve you're employing and its inherent flow characteristics. Flow properties vary greatly across valve types and their disks (or profiles). The flow characteristic is the change in flow rate in response to a change in valve position. The linear features of globe control valves are preferable, while the non-linear flow characteristics of butterfly and gate valves might pose control issues. Manufacturers add specifically designed disks or flow orifices that provide a custom flow profile to establish a linear flow characteristic via a non-linear control valve.
Classic Controls
https://classiccontrols.com
+1 863-644-3642

FLEXIM’s Thermal Energy Meters Support Your Efforts Towards More Energy Efficient Buildings and Facilities

FLEXIM’s Thermal Energy Meters

Reducing energy consumption and costs is a significant priority for all industries. Energy efficiency usage has never been more critical than now, whether to meet energy regulations and standards or to improve the company's carbon footprint and bottom line. 

ISO 50001 or EMAS Energy Management Systems are the most powerful organizational tools for achieving efficiency. However, implementing and maintaining an energy management system can be challenging to obtain accurate energy consumption data. 


To improve efficiency, it is necessary first to assess the current situation. Measurement entails data points to learn about the energy flows from the boilers, chillers, and air handlers that serve the system's consumers. 

Installing data acquisition tools can become a massive and even overwhelming task given the various types of energy flows in heating and cooling systems, compressed air lines, steam supply, and high-temperature heat transfer oils. Each has its own set of characteristics and requirements when it comes to metering systems. 


The ultrasonic, non-invasive transit time principle FLEXIM is the ideal solution for all of these tasks. This measuring principle is a one-size-fits-all solution because it applies to liquids, gases, and steam and can handle temperatures ranging from -40°F to 465°F and even higher.


Classic Controls
https://classiccontrols.com
+1 863-644-3642

Automated Stainless Steel Ball Valve and Actuator Systems

Stainless Steel Ball Valve and Actuator

Ball valves regulate flow by rotating a spherical ball within the valve, which contains an opening or port through which liquid can flow when the valve turns to align with the flow direction. The port becomes perpendicular to the flow direction when the ball rotates 90 degrees, preventing fluid from passing through the valve. Using stainless steel in a flow control ball valve is advantageous because it is highly corrosion and contaminant resistant, requiring less cleaning and maintenance and often providing a longer service life. 

Spring return, double acting, fail open and fail close stainless steel pneumatic actuators are available. One of the benefits of using a stainless steel actuator is its corrosion resistance and standing up to the most harsh atmospheres. Stainless steel pneumatic actuators are ideal for heavy-duty automation, particularly in corrosive environments. NAMUR-compliant stainless steel actuators with a durable stainless steel body continue to perform in the harshest applications. 

Stainless steel actuated ball valves from Classic Controls provides exceptional accuracy and dependability in flow control and open/close operations, critical in manufacturing, chemical, oil and gas, wastewater, petroleum processing, and other installations where corrosion is an issue. 

Classic Controls dedicates itself to providing you with the best valve specifically for your application. Call +1 863-644-3642 or visit https://classiccontrols.com for more information on stainless steel valves.