Industrial fluid systems should be designed and built with the right components to reliably function as intended. Valves play an important role here, allowing operators to effectively control system fluid flow to best suit the application’s needs.
Fluid system design can be complex, requiring many considerations. It may not always be readily apparent which valve is right for your application. Do you need to stop and start flow? Control the direction of flow? Regulate flow level? Or do you need to protect your system from overpressure?
These are all questions that should be asked when deciding how to select a valve for your fluid system. In this post, we will explore different types of industrial valves and offer tips to help you make the right choice for your applications.
Fluid systems can be dangerous if installation and operation best practices are not followed. Many fluid processes operate at elevated pressures and temperatures. Additionally, some fluids may be hazardous, and if any leaks occur, operators may be at risk.
Valves play critical roles in enabling safely functioning fluid systems. For example, a safety shut-off valve or pressure relief valve can prevent your system from reaching overpressure, a potentially dangerous scenario that may lead to a blowout.
A valve’s ultimate responsibility is to control flow. Flow is defined as a fluid’s movement in a steady and continuous way through your system. As a fluid or gas flows, it moves from a higher pressure to a lower pressure. Typically, flow is measured in flowmeters, and is recorded in terms of a ratio of distance or volume per unit of time (e.g., meters per second, gallons per day, liters per minute, etc.).
Valves permit flow based on factors including the diameter of its end connection and the valve’s flow path. To help understand a valve’s ability to control flow, manufacturers typically provide a flow coefficient, or Cv, along with the supplied valve. A higher Cv means a higher flow rate, but a higher Cv is not necessarily beneficial—depending on the valve type and application, some valves may come with a Cv of near zero.
Use our Cv Calculator to determine Cv or flow based on pressures, flow rates, temperatures, and media within your system.
The many valves available today serve five primary functions, listed below along with their industry-standard symbols commonly found in piping and instrumentation diagrams (P&IDs):
With a fuller understanding of flow and how different types of valves can help control it, you will be better equipped to make the proper selection in your fluid system design. This article, however, is just a primer. As a next step, consider reading more about using the proven STAMPED industrial valve selection method in this related article.