Globe and ball valves are crucial parts of fluid control systems.
Choosing the appropriate valve for a particular industrial process requires understanding its design, functionality, and applications.
What is a Ball Valve?
It is a kind of quarter-turn valve that regulates fluid flow, often water, gas, oil, or other fluids, using a hollow, perforated, pivoting ball (a “floating ball”).
Looking at the ball valve design, they have a hole or port that runs through the center. This is when it is lined up with the fluid flow channel. In this position, it allows fluid to pass through.
It rotates 90 degrees when closed, obstructing the flow route and stopping fluid passage.
What is Globe Valve?
It is a linear motion valve that regulates fluid flow via a pipeline. The name arises from the valve body, which has a globe-like shape.
Globe valves are adaptable and often used in many different sectors to control the flow of fluids, gases, and steam.
How Ball Valve vs. Globe Valve Compare
While the sign for a globe valve resembles a circle with a stem and represents the linear motion of the valve, the symbol for a ball valve is more rounded, indicating a spherical mechanism.
The symbols’ locations might indicate whether or not the valve is open or closed.
For instance, the ball valve symbol denotes a closed valve if it is perpendicular to the flow. If the stem of a globe valve shows in the highest position, the valve is closed.
In a globe valve, the plug or disc glides linearly up and down to regulate flow, whereas the ball in a ball valve spins to open or close the flow.
Both symbols include an arrow designating the flow direction via the valve. Understanding how the valve fits into a system depends on knowing this detail.
Advantages of Ball Valves
Quick On/Off Operation
Ball valves are well renowned for their rapid quarter-turn action. All it takes is a 90-degree movement of the handle or actuator to completely open or close.
They are perfect for applications requiring quick flow control.
Modest Friction Loss
Ball valves have modest pressure drops or friction losses when open due to their unhindered fluid flow.
Good Sealing Properties
When closed, ball valves provide a tight seal that reduces leakage and prevents backflow.
Versatility in Media Handling
With the right seat and material choices, ball valves are versatile in the media they can handle, handling a variety of fluids such as liquids, gases, and even slurries.
Less Prone to Erosion and Corrosion
Due to their streamlined design, ball valves are less prone to be harmed by flowing fluid particles. They are thus appropriate for applications where resistance to corrosion and erosion is crucial.
Ball valves are durable and able to endure high temperatures and pressures. They frequently consist of durable materials like brass or stainless steel.
Advantages of Globe Valves
Exact Flow Control
Globe valves are excellent at throttling and managing fluid flow rates. The linear motion of the disc or plug enables exact adjustments, making them perfect for uses requiring precision control.
Excellent Shut-Off Capabilities
Globe valves offer good shut-off abilities. The disc securely rests against the valve body when fully closed to reduce leakage. In situations where a tight shut-off is essential, this is significant.
Easy to Maintenance
Globe valves are frequently simpler to maintain and replace. Internal elements are frequently easier to access, and the design enables simple repair of components like the disc and seats.
Particularly well-suited for high-pressure systems are globe valves mounted on trunnions. The trunnion supports the valve, enabling it to withstand higher pressure loads.
Suitable for Handling Fluids at High Temperatures
Use globe valves in situations where high temperatures are present. They are capable of withstanding high temperatures without losing performance.
Ball Valves Limitations
Limited Precision Flow Control
Globe valves are better at precise flow control than ball valves. Even while they can control flow, especially at lower flow rates, they might not have as much fine-tuning flexibility as globe valves.
Prone to Cavitation in High-Speed Flows
Ball valves are sometimes prone to cavitation in high-speed fluid applications. Rapid pressure fluctuations can cause vapor bubbles to form in the fluid, which can cause cavitation, which can erode and harm the valve’s internal parts.
Slurries and Extremely Viscous Fluids
Ball valves may not be the best choice for handling slurries and viscous fluids. The ball’s spherical shape can retain solids, which might clog the system or limit efficiency.
Limited in High-Temperature Applications
Ball valves, especially those with soft seats, may not be appropriate for high-temperature situations. Performance and dependability may suffer as a result of seals and seats deteriorating.
Potential for Seatwear
Over time, the seats of ball valves may deteriorate in applications involving aggressive fluids or high cycle rates. Leaks may result from this, necessitating more regular repair.
Limitations of Globe Valves
Higher Pressure Drop
When completely opened, globe valves tend to have higher pressure drops than ball valves. These increase fluid flow resistance, which is beneficial in high-flow applications.
In contrast to the rapid quarter-turn action of a ball valve, globe valves function with a linear motion that often takes longer.
Susceptible to Erosion and Cavitation in Certain Configurations
Globe valves can be vulnerable to erosion and cavitation in high-velocity flows or arrangements that encourage turbulence.
Potentially More Sophisticated Design
Compared to ball valves, a globe valve’s interior components, particularly the more sophisticated are hard to reach for maintenance and repair. This results in a prolonged downtime during maintenance procedures.
Not as Well-Suited for High-Temperature Fluids in Some Configurations
Frequently use globe valves in high-temperature applications. Some designs might not be ideal for high temperatures due to possible difficulties with seals and packing materials.
Less adaptable for Gas Applications
Globe valves may not be as adaptable in managing gas flow. In gas applications, the linear motion might not offer the same amount of control.
Design and Structure (Compare Various Valve Parts)
Flow Control Mechanism
Ball valves employ rotation to regulate flow, whereas globe valves use linear motion to provide exact control.
Ball valves open and close swiftly with a quarter-turn motion. Globe valves operate more slowly because of linear motion.
Ball valves employ seats on either side of the ball to produce a seal as their sealing mechanism.
Globe valves have a unique “T” or “Y” form, whereas ball valves have a more rounded, spherical body.
Internal Component Complexity
Globe valves frequently have more internal components than ball valves, which makes them more complicated.
Versatility in Flow Control
Ball valves are well-suited for applications that require rapid on/off control. Globe valves excel in situations where precise throttling and flow regulation are crucial.
Versatility in Flow Control
Ball valves are highly suited for applications that call for quick on/off control due to their versatility in flow control. Globe valves perform well in applications where precise flow control and throttling are essential.
Complexity of Internal Components
Globe valves have more internal components, making them more complex than ball valves.
Type of Motion
Ball valves work circularly, whereas globe valves move linearly. Therefore, these valves control fluid flow differently because of the different motion types.
Speed of Operation
Because of the quarter-turn mechanism, ball valves operate more quickly. They require a tiny movement to completely open or close.
Because the disc or plug must travel up or down along the valve seat, globe valves work more slowly.
Globe valves are favored when accurate throttling and flow regulation is required, whereas situations that call for quick on/off control use ball valves.
Flow Control Precision
Ball valves are more appropriate for applications requiring quick on/off control, although they could not offer as much fine-tuning as globe valves, particularly at lower flow rates.
Globe valves are the best choice for situations where exact flow rate modifications are essential since they excel at precise flow control.
Flow Control and Head Loss.
- Flow Control Precision
Ball valves are ideal for applications that call for quick on/off control. They can initiate or halt the flow of fluids rapidly and effectively.
- Limitations in Throttling
Although ball valves control flow, they may not be as precise as globe valves at lower flow rates.
It is hard to get precise flow control when using a ball valve.
- Applications for High-Flow Systems
Ball valves are effective in high-flow systems when rapid, complete opening or full shutting movements are required.
- Precision Flow Control
Globe valves are excellent at controlling exact flow.
Flow rate modifications are possible thanks to the plug’s or disc’s linear motion.
- Throttling Capability
Globe valves are suited for circumstances where precise control of flow rates is required since they are for throttling applications.
- Capability for Low Flow
Situations requiring precise control of low flow rates, which may be difficult for ball valves, are ideally suited for globe valves.
- Pressure Drop
Ball valves usually offer a clear channel for fluid flow when completely opened, producing a little pressure drop or head loss.
- Cavitation Risk
Ball valves are prone to cavitation in high-velocity fluid applications.
Rapid pressure fluctuations can cause vapor bubbles to form in the fluid, which can cause erosion and harm to the valve’s internal parts.
- Higher Pressure Drop
When completely opened, globe valves tend to have higher pressure drops than ball valves.
They raise the fluid flow resistance, which may be significant in high-flow situations.
- Reduced Cavitation Risk
Globe valves frequently have a lower cavitation risk than ball valves do.
Its design makes it less likely that there will be unforeseen pressure increases because the flow may change gradually.
- On/Off Control in High-Flow Conditions
Ball valves are fantastic for applications that need quick on/off control, particularly at high flow rates. Examples include turning off pipes for industrial activities or the primary water supply in buildings.
- General Utility in Fluid Handling
Use Ball valves in several fluid handling applications because they are adaptable and can manage a variety of fluids, including liquids, gases, and even slurries.
- Systems With minimal maintenance
Because they are less prone to wear and tear than certain other valve types, use them in systems with minimal maintenance and long-term reliability.
- Isolation in Piping Systems
The valve must be completely open or fully closed to stop the flow. Plumbing in homes and industrial operations both frequently exhibit this.
- Systems Under High Pressure
Applications like the oil and gas sector and ball valves, particularly those with trunnion-mounted balls, are ideally suited.
- Natural Gas and Compressed Air Systems
Employ Ball valves in gas systems because of their rapid on/off action. They work well with compressed air systems as well.
- Marine and Shipbuilding
Use Ball valves in maritime applications, including shipbuilding, where they can manage fluids like saltwater, gasoline, and other substances.
- Precise Flow Control
Globe valves are excellent at giving fine flow rate control. Use them in situations where fluid flow management is essential.
- Boiler Feedwater Systems
Globe valves manage the water flow into the boiler that produces steam.
- Cooling Water Systems
Globe valves are used in cooling water systems to control water flow, which regulates temperature in industrial operations.
- Steam Systems
They have uses in steam systems for the steam flow for several activities.
- Situations with High-Pressure Drops
Globe valves are appropriate when a higher pressure drop is required, such as in some HVAC systems.
- Applications for Throttling
Because they are made expressly for throttling, they are appropriate for operations where the flow needs to change within a particular range.
- Applications with Sudden Changes in Flow
Since they are less susceptible to cavitation than ball valves, they have a value in systems where sudden changes in flow may occur.
With the information in this guide, you can conveniently decide whether to choose ball valves or globe valves. At D&R, we help you choose a perfect valve for all your applications – contact us now.