Globe Valve Vs Ball Valve (Comprehensive Analysis)

What Is A Globe valve?

Globe valves are indispensable fluid control devices in piping systems. Their operating principle is based on the vertical movement of the valve flap along the center line of the valve seat. 

In terms of technical parameters, the flow coefficient CV of the globe valve has an approximately linear relationship with the valve opening, showing a fast-opening characteristic, which is conducive to precise adjustment. 

Modern globe valve design incorporates several advanced technologies, such as intelligent actuators, carbide coatings, CFD analyses and 3D printing technology. These innovations have not only improved the performance and reliability of the valves but also realised intelligent functions such as remote control and condition monitoring. For example, the -196°C class cryogenic globe valve used in the LNG transmission system is made of deep-cooled austenitic stainless steel to ensure reliable operation under extreme conditions.

Globe Valve Configurations

Globe valves are available in three basic configurations:

T- or Z-type globe valves, Y-type globe valves, and angle-type globe valves. Each type is designed to meet different functional and installation requirements.

• T- or Z-style globe valves are the most common and are known for their simple design.

• Y-globe valves offer a lower pressure drop, making them ideal for high-pressure applications, while angle-globe valves redirect flow at a 90-degree angle, optimizing space in tight installations.

Disadvantages Of Globe Valve

However, globe valves are not perfect. In the actual use of the process found that they are fully open or fully closed state of the best results, and partially open when the medium may be caused by high-speed flow valve vibration, and the valve valve and the valve seat may form a cavity between the valve, resulting in cavitation phenomenon, increasing the wear and tear of the valve and noise.

Globe valve flow path is ‘Z’ shape, easy to cause a large local pressure loss, will lead to its CV is usually lower than the same diameter of the ball valve and gate valve. And because the valve needs to overcome the medium pressure and sealing surface friction, opening and closing the required operating torque is larger.

Ball valve is a kind of valve widely used in fluid control system, involving civil and industrial use. Its core component is a spherical spool with a through hole. The working principle of the ball valve is based on the 90-degree rotation of the sphere, through the control of the sphere in the channel and pipeline alignment to achieve open, close or regulate the fluid flow and other states.From the technical parameters, the ball valve has excellent performance indicators. Its pressure rating is up to PN420 (ANSI 2500 class).

The structure of the ball valve mainly includes the valve body, ball, seat, stem operating mechanism, and other components. According to the structure of the ball and seat, it can be divided into floating ball design and fixed ball design. The floating ball design can achieve self-sealing under high-pressure differential conditions, while the fixed ball design is suitable for larger-diameter and higher-pressure occasions. Ball valves are available in a variety of drive modes, including manual, pneumatic, electric hydraulic, etc., which can be selected according to different application requirements.

In practice, ball valves show a variety of advantages. First of all, its quarter-turn operation mode makes the switch quickly, especially suitable for the need to quickly cut off the occasion. Secondly, when fully open, the flow path is smooth and the pressure loss is small, which is especially important in large-diameter long-distance pipeline. Furthermore, the ball valve sealing performance is excellent, two-way sealing ability, suitable for a variety of media.

Ball Valve Design Categories

Ball valves can be classified into several categories based on various design features:

Housing Structure:

1-piece ball valves

2-piece ball valves

3-piece ball valves

Port Size:

Full port ball valves

Standard port ball valves

Reduced port ball valves

Number of Ports:

2-way valves

Multiport valves

Disadvantages Of Ball Valve

However, the ball valve also has some limitations. For example, in regulating applications, the flow characteristics of ordinary ball valves is not as ideal as the regulating valve, although it can be improved by V-shaped notch ball, but there are still some limitations. In addition, in the medium containing solid particles, the sealing surface of the ball valve is susceptible to wear and tear, the need to choose a special material or structure of the ball valve.

Ball valves have a hollow ball that rotates inside the valve, requiring a simple 90-degree rotation for quick shutoff and full flow. In contrast, globe valves utilize a disc that moves vertically through the stem for more precise control of fluid flow.

What are the similarities between globe and ball valves?

Both valves are designed as shut-off devices that open or restrict the flow within a pipeline as needed.

Globe and ball valves can be operated manually by a handle or lever or automatically by an actuator.

In summary, although globe and ball valves differ in design and operation, they both have the primary function of controlling and stopping the flow of fluid in a piping network and offer both manual and automatic operation options.

Internal Structure And Mechanism:

Globe valve CV is relatively low compared to the ball valve, full bore design of the ball valve flow coefficient Cv can reach more than 95% of the gate valve of the same caliber, while the globe valve can only reach 60-70% of the intrinsic flow characteristics of the fast-opening characteristics, the flow rate of small openings change drastically. The flow characteristics of the ball valve is close to equal percentage characteristics, more suitable for flow regulation.

Pressure Loss:

When discussing valves, it is critical to understand head loss. Head loss is the reduction in pressure as a fluid passes through a valve and affects the efficiency of the overall system. The design of the valve plays an important role in pressure loss.

Because globe valves have a “Z” shaped flow path, the fluid must change direction several times. This leads to higher localized pressure losses, with pressure loss coefficients ζ typically ranging from 4 to 6. This complex path leads to more turbulence and resistance, which results in a greater pressure drop.

On the other hand, the performance of a ball valve is quite different. When fully open, the flow path in a ball valve is smooth and unobstructed with minimal pressure loss. At this point, the pressure loss coefficient ζ is significantly lower, usually between 0.1 and 0.3. This streamlined flow path transmits fluid more efficiently and maintains higher pressure levels than a globe valve.

In summary, although globe valves can effectively control flow, they are bound to have higher head losses due to their complex flow paths. Ball valves, with their simple design, are the best choice for critical applications where pressure losses are minimized.

Sealing Performance:

Globe valves are available with API 598 Class VI seals, and metal seals are available up to Class IV or Class V.

Ball valves are available with soft seals up to API 598 Class VI seals and metal seals typically up to Class V seals.

Temperature Range

Metal Sealed Globe Valves are available for temperatures from -196°C to 550°C.

Soft-sealed ball valves are normally suitable for temperatures from -29°C to 180°C, metal-sealed ball valves can be extended to -196°C to 450°C

What Similarities Do Globe Valves And Ball Valves Share?

• Functionality: Both globe and ball valves serve as shut-off devices, capable of allowing or halting the flow of liquids and gases through piping.

• Operation: They can be operated using manual levers or automated systems, offering flexibility in system control.

Working

Globe valves use the valve flap along the centre line of the valve seat of the linear lift movement to control the fluid, through the mandatory seal to achieve media cut-off. Ball valves use the ball of 90 degrees to control the fluid, a quarter of the rotation can be completed full open or full closed.

Application Scenario：

Globe valves are used where frequent adjustments are required, typically in steam, high-temperature and high-pressure systems. These valves excel in throttling applications, and their design allows for finer adjustments.

Ball valves, on the other hand, are suitable for applications where quick shutoff is required, and are widely used in oil, gas and chemical industries. Ball valves excel as shut-off valves due to their quick operation and reliable sealing. This makes ball valves the best choice for applications that require tight sealing and fast response, ensuring minimal leakage and operational efficiency.

In summary:

Globe valves: best suited for throttling and fine control, especially in challenging environments such as steam and high-pressure systems.

Ball Valves: Suitable for fast closing and tight sealing, commonly used in industries where a quick and safe stopping of flow is required.

Installation Position Of Globe Valve

Globe valves are used where frequent adjustments are required and are commonly used in steam, high-temperature and high-pressure systems. They excel in throttling applications for precise flow control. They are ideal when you need to precisely regulate fluid flow.

On the other hand, ball valves are suitable for applications that require fast shutoff and are widely used in oil, gas, and chemical industries. They offer excellent performance as shut-off valves, providing a tight seal with very little effort. This makes them ideal for applications that require a completely fast shutoff.

Ultimately, the choice between a globe valve or a ball valve depends on the specific requirements of your application. If precise flow control is your priority, then globe valves are the best choice. However, for applications that require fast and reliable shutoff, ball valves are a better choice.

It is important to note that the direction of installation of the globe valve must be confirmed and not reversed. Reverse installation can lead to a series of serious consequences, including reversal of the direction of water flow, unstable temperature control, accelerated wear of equipment, flow regulation failure, increased safety hazards, reduced system efficiency, maintenance difficulties, and the potential risk of media leakage.

When selecting a valve manufacturer for commercial use, a combination of valve type, manufacturer reputation, quality certifications, customized service and overall value need to be considered. And quality customer support and after-sales service can significantly improve the experience, especially when it comes to technical problems. In addition, choosing a manufacturer that can provide customized solutions can better meet specific needs, thus improving the overall efficiency of the system.

At the same time, balancing cost and performance is equally important. One should not focus too much on the initial cost at the expense of the durability of the valve, leading to increased maintenance costs later on. The most scientific thing is to ensure that the selected product not only meets the current needs but also has long-lasting durability and reliability.

Comprehensively speaking, different scenarios, different business needs often need to be able to perfectly match the valve. If you have a special industry, and still can not determine how to choose the right valve, welcome to contact our valve manufacturing experts at any time, we will give you tailored product solutions to meet your specific needs, just enter your information, click to send can be, ready to serve you!