Control valves are a part of the industrial manufacturing system. They are designed to process valves & flow control of fluids in a system. The main objectives of these valves are to shut, open or regulate fluid flow. Today, several types of valves are manufactured.
When it comes to process control, valves are a critical component. They may be just a single component, but they are important nonetheless. You’ve probably heard of some common valves and their respective applications, but they certainly need to hold some of the answers. This article will discuss what’s involved in choosing an appropriate process control valve.
Process Control Valves Defined
A process control valve is designed to control a system’s flow while operating at any pressure provided by the fluid being transported and is used to regulate fluid flow through a system. They can be classified as check valves or passive valves, depending on the method of operation.
Check valves are more commonly used in systems where high pressure can be present, and with them, you can prevent air from entering a system.
These are also known as safety valves, which prevent hazardous situations from occurring within certain areas of the process by preventing dangerous bursts of high pressure and steam inside it. They are widely used in pipeline networks, industrial machines, and chemical processes.
Types of Control Valves
Control valves are used for controlling the flow of fluids in a complex system and perform other functions, such as regulating pressure and temperature or diverting flows. While they are integral parts of most systems, they can be damaged during use, so they need replacement or repair.
There are many control valves today, each with specifications to work efficiently under different conditions. The different types mentioned below are ideal for various applications and industries, such as:
1. Rotary Valves
This type of valve is widely used in industrial applications for transferring liquids and gases between tanks, pipelines, etc. The mechanism of this kind of valve consists of one or more openings within a cylindrical body. The opening allows the flow and control of liquid within the vessel.
This can be achieved using a series of passages formed within the body and a removable plug that rotates through its axis to close the passage. In some situations, this kind of valve may perform better than other types since it does not have moving parts affected by debris, coolant, or steam.
2. Globe Valves
Linear globe valves are used in applications that require the control of flow rates and pressures. The most common use of linear globe valves is in the gas distribution industry. This is because these valves allow easy access to internal elements, making them ideal for piping applications where access is needed for service or maintenance.
3. Three-Way Control Valves
Linear three-way control valves are used to control a liquid’s flow, making it easier to mix two different fluids. They are used in various applications, including water supply, air conditioning, and heating. In the case of water supply, you can use them to manage water flow between an upstream storage tank and a downstream user.
Air conditioning and heating systems commonly use linear three-way valves to distribute cooling or heating throughout an entire building and isolate different zones.
4. Angle Valves
Linear angle valves are used in the process of circular motion and manufacturing. They work as a mechanical interlock between two sectional pipes. A linear angle valve consists of two stacked valves located at different heights, typically a few inches apart.
They are versatile and can be installed in many places, such as oil rigs, water intake systems, and naval vessels. The flow rate requires huge pressure. This pressure needs to be controlled, which is why linear angle valves were developed.
How To Choose The Appropriate Process Control Valves?
Process control valves are essential in optimizing production, quality, and reliability. They help reduce energy consumption, protect against inefficiencies and improve plant efficiency.
Choosing the right process control valves can seem daunting, making it tempting to opt for the cheapest one. While cost is certainly a factor, you’ll need to consider all the other factors — such as durability and flexibility — before choosing your valves.
To ensure safe operation, the design of a control valve is crucial. It must operate at a stable speed and within designed parameters.
2. Flow Control
Since a valve will operate 24/7, you need to ensure that the valve meets all your needs and tasks. You should understand that valve flow characteristics may vary across different applications. For this reason, choosing a valve that meets the required flow range is vital, whether high or low.
Parameters affect the flow control characteristics of a valve. The valve should maintain a consistent flow rate across all temperatures, pressures, and conditions. A good quality flow control valve, such as rexroth valves, will also have equal or percentage control across varying temperatures or several variables.
3. Size and Type
The right size valve can make all the difference regarding reliability and performance. It should be able to perform functions such as divert flow, adjust flow, pressure relief, mix flow, prevent backflow, and divert flow.
4. Material Grades
It is very important to know the material grades of industrial valves, and an important aspect to consider before you buy. Stainless steel material grades are relatively easy to find. Each grade has its features, strengths, and weaknesses, depending on the industry it’s used in.
When you’re in the process control business, it’s important to understand valve selection. You’ll need to choose a valve that fits your application and is reliable long enough while remaining affordable. There are numerous process control valves available for you to choose from – each with its features and benefits.
Understanding the different types can make narrowing down your options and choosing the right valves easy.