Flow control valves and throttling valves are two of the most widely used in the waterworks industry. They are both used for a wide range of industrial applications, ranging from manufacturing plants and factories to wastewater treatment. However, these valves are very different in how they operate, and they can't always be used interchangeably.
Flow Control Valves
What is a Flow Control Valve, and How Does It Work?
Flow control valves are specialty valves that offer precise automatic control over flow rate, regardless of water or liquid pressure. You can preset the maximum flow rate, and fluid flow will never exceed that rate. These valves allow you to control flow remotely and don't require in-person manual monitoring.
The fact that flow control valves control pressure automatically makes them extremely popular options for many industries. The valves' built-in controls respond to changes in liquid pressure, such as pressure drop, and adjust accordingly. They do this by slightly opening or closing to change the outlet pressure and speed up or slow down the flow rate.
Key Benefit: Flow control valves help reduce wear and tear on major components within a system, such as motors and pumps, by controlling flow rates and pressure. This not only improves system efficiency but also extends the lifespan of critical equipment. For example, controlling the speed of a motor with a flow control valve reduces stress on its components, minimizing damage and maintenance costs over time.
Common Flow Control Valve Applications
Because flow control valves don't require manual adjustment, they are extremely popular in a number of industrial applications. They are frequently used in areas that are tough or impossible to access quickly in the event that the valve needs to be opened or closed.
Flow control valves are also a popular option in situations that require precise flow control. This includes settings such as:
- Gas and oil pipelines
- Medical device manufacturing plants
- Chemical processing facilities
- Wastewater treatment facilities
- Pharmaceutical production
- Food and beverage production
Flow control valves are very versatile tools that can filter a wide range of air and liquids. From oil and gas to water, steam, and more, flow control valves can get the job done.
Throttling Valves
What is a Throttling Valve and How Does It Work?
Throttling valves have a similar job as that of flow control valves in that they help control media flow through pipes and other components. However, many throttle valves require manual operation to open and close. In other words, someone has to physically turn or manipulate the throttle valve stem or handle to open and close it.
The main exception to having to manually operate a throttle valve is in the automotive industry. Throttle valves in cars, trucks, tractors, and other vehicles open and close automatically, similar to flow control valves.
Throttle valves, which include globe valves, are also often used to severely reduce the flow rate of liquid through a medium. This is because the main purpose of a throttling valve is to reduce the pressure in any given system. As such, they must be able to handle a large amount of pressure drop over a long period of time.
Common Throttling Valve Applications
Throttle valves are used in a wide range of applications, largely because there are so many different types. From globe valves to the classic butterfly valve, there are numerous options to choose from. Additionally, throttle valves are fairly affordable and durable, which makes them a good option for coarser applications.
The main place that throttling valves are used is in the automotive industry. However, they're also implemented in the following industries:
- The HVAC industry uses them in air conditioners and refrigerated systems
- Lawnmowers, weed-eaters, and other components with small engines
- Steam-powered and hydraulic systems
- Gas and oil production facilities
- Pharmaceutical and chemical processing
Main Differences Between Throttle Valves and Flow Control Valves
Now that you know more about throttle and flow control valves and how they're used, let's examine the main differences between them.
Functionality
The biggest difference between throttling and flow control valves is in how they function. Flow control valves don't require hands-on manipulation to alter flow rate and media flow, whereas some types of throttle valves do. Additionally, the only job of throttle valves is to reduce media flow, whereas flow control valves can increase or decrease flow accordingly.
Precision
Flow control valves also offer more precision than throttle valves do. Throttle valves are more of a coarse valve that simply reduce media flow to a safe rate. Flow control valves, on the other hand, offer precise control up to a single psi.
Applications
Because of their differences in functionality and precision, these valves are used in different ways. Flow control valves are a better option for tough-to-reach areas or situations where precise control is necessary. They also reduce wear and tear on system components, extending the lifespan of motors, pumps, and other critical parts.
Throttling valves are a better option when you're on a tight budget or simply need to reduce flow rate without too much precision. They're also a better option in extreme temperatures, as they hold up better under the elements.
Design and Mechanism
Because flow control valves require more precision, they are designed differently than throttling valves. Flow control valves have an actuator and thermometers and flow meters, whereas throttling valves have a very basic construction with a handle and valve stem.
Choosing the Right Valve For Your Needs: Factors to Consider
Whether you need a flow control valve or a throttle valve largely comes down to how much control you want over media and flow rate. If you need precise control and the ability to increase or decrease pressure, a flow control valve is the right option. However, when you only need to reduce media flow without much precision, throttle valves are the way to go.
Other factors to consider include:
- Pipe Size: Throttling valves work better in smaller pipes, whereas flow control valves work well in all pipe sizes.
- Temperature: Throttling valves are the better option when operating in extreme temperatures, whether hot or cold.
- Material: Flow control valves also work with more materials and components than throttling valves, making them a more versatile option.