Gate Valve vs Ball Valve - How They Work

Figure 1: Ball valve (left) and gate valve (right)

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Gate valves and ball valves are the most commonly used flow control valves in the market. They are generally used to control the flow of liquid and gases. Although they are used in similar settings, there are a few important differences between these two valves. We discuss the differences between gate and ball valves and how to choose between them.

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• Ball Valves

• Gate Valves

 

Operation differences

A ball valve uses a rotary ball with a bore and a stem as seen in Figure 2. When the handle attached to the stem is turned, it rotates the ball to open or close the valve. This valve is also called a quarter turn valve because the handle only needs a 90° turn (quarter turn) to allow or block the flow of the media. The valve is open when the handle is parallel to the pipe and it is closed when the handle is perpendicular to the pipe. For a more in-depth analysis of ball valves, view our ball valve technical article.

Figure 2: Ball valve stem (A) and rotary ball (B)

A gate valve uses a gate to control the flow of the media. A gate is a solid disk structure that is connected to the stem, as seen in Figure 3. The gate is lifted to open the valve and is returned down to its original position to close the valve. The valve is accompanied by a bonnet which when rotated controls the position of the gate. This valve is also called a multi turn valve because it takes more than a 360° turn to fully open or close the valve. For a more in-depth analysis of gate valves, view our gate valve technical article.

Figure 3: Gate valve stem (A) and gate (B)

Advantages and Disadvantages

Due to the differences between gate and ball valves operation and design, there are certain advantages and disadvantages to each. Depending on your application, one is typically better than the other. View our table below for key differences between a gate and ball valve.

 

Ball valve

Gate valve

Shut off mechanism

Fast shut-off with only a quarter turn (90° turn) to close the valve.

Slow shut off as it requires more than a 360° turn to shut off the valve.

Water hammer

Fast opening and closing may cause water hammer.*

Slow opening and closing reduces the risk of water hammer.*

Visual detection

Open or closed state of valve can be visually detected with position of the handle.

Difficult to detect the open or closed state of valve.

Cost

Typically more expensive than a gate valve of the same specifications.

Typically cheaper than a ball valve of the same specifications.

Installation space

Requires more space than a gate valve to accommodate for quarter turn handle.

Requires relatively less installation space than a ball valve.

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Size

Better suited for bore sizes below 2".

Better suited for bore sizes above 2".

Leakage

Provides tight seal even if used after a long period of time.

More prone to leaks than a ball valve.

Durability

Durable and less prone to damage

Valve stem can be prone to corrosion making the valve less durable.

* If the flow is abruptly stopped by rapidly shutting off the valve, pressure builds up due to the momentum of the moving medium and this causes a short pressure surge. The pressure surge causes a noise which sounds like the pipes were struck by a hammer. A powerful water hammer can cause a rupture or leak in the system. To find out more about water hammer, read our water hammer technical article.

Selection criteria

The following criteria can be considered before selecting between a ball valve and gate valve:

1. Ports: A gate valve has 2 ports, while a ball valve can have more than 2 ports.
2. Flow Capacity: A gate valve can provide larger flow capacity than a ball valve as they are typically offered in larger diameters.
3. Opening and closing speed: A ball valve is better suited for applications that require faster opening and closing speed or during emergencies due to its quarter turn on/off operation. A gate valve requires more than a 360° turn, making it slower than a ball valve to operate.
4. Sealing: A ball valve provides a tight seal and has complete shut off characteristics as compared to a gate valve. Therefore, ball valves are better suited for applications like natural gas where a proper seal long-term is important.
5. Pressure: Both ball valves and gate valves are suitable for low pressure applications. However, for high pressure applications a gate valve is better suited. This is due to the fast opening/closing of the ball valve that may cause a water hammer.
6. Cost: A ball valve is generally more expensive than a gate valve of the same specifications. However, a ball valve is typically more durable and requires less maintenance compared to a gate valve. So, a ball valve may be more economical long-term.
7. Connection: The choice of connection to the pipe is an important factor for both valves. To learn more about this important subject, read our Ball Valve Connection Types technical article. 

Common applications

Both ball valves and gate valves are commonly used in residential and industrial applications.

• Gate valves are generally found in older plumbing systems and in applications where frequent shut off is not required. Large water supply lines use gate valves due to their straight flow path and less flow restrictions. Ball valves are increasingly used in new plumbing systems with frequent shut off requirements.
• Gate valves are used for application with slurries and viscous media because they are easier to clean and maintain. Ball valves are not desirable because they are difficult to clean, and the slurry particles may damage the rotary ball.
• Gate valves are used in power plants, mining and water treatment applications which are high temperature and high-pressure environments.
• Ball valves are commonly used in fire protection systems and marine applications. They are best not used in food, beverage and pharmaceutical applications as ball valves are difficult to clean and may cause contamination.

FAQ

Which is better gate valve or ball valve?

It depends on the application. A ball valve is better suited for smaller flow rates, anything requiring more than 2 ports, or for durability/sealing concerns. A gate valve is typically cheaper, better for higher flow rates, and requires a smaller installation space.

What is the difference between gate valve and ball valve?

The main difference is in the operation. A gate valve moves a solid disk up and down to open/close the orifice. A ball valve rotates a ball (the orifice) with a bore in it 90 degrees to open/close the valve.

What is a ball valve used for?

A ball valve is used to control the flow and is typically used as a shut off valve.

When would you use a gate valve?

A gate valve is ideal for applications that have slurries, large flow rates, cost sensitive, and for shut off purposes.

View our online selection of gate valves and ball valves!

• Ball Valves

• Gate Valves

A gate valve is a device used to stop and start the flow of liquid and isolate sections of a water supply as required. Sometimes referred to as a sluice valve, there are many different types of gate valves suitable for various applications in utility distribution, industrial and HVAC pipeline settings. Let’s take a look at what a gate valve is used for, the differences between the most common types, and the things to consider when specifying a gate valve.

WHAT IS A GATE VALVE?

A gate valve is a type of linear valve used to isolate areas of a water supply. As the name suggests, it acts like a gate that shuts off the flow and opens it again when needed.

Gate valves work via a gate or wedge that lifts (opens) or lowers (closes) into the path of the flowing liquid. Motion is produced by an actuator that is connected to the stem of the gate, which may be manual, electrically, pneumatically or hydraulically powered. They may have a rising stem, meaning it is fixed to the gate, or a non-rising stem, where it is fixed to the actuator and remains within the valve body. The latter is most commonly used in the waterworks industry and is suitable for underground applications where there is limited vertical space. 

Gate valves may also sometimes be referred to as stop valves, line valves, wedge gate valves and sluice valves, but they are not to be confused with sluice gates or penstocks. These are altogether larger devices used to severe the flow of sewage and water in treatment plants and drainage systems, etc.

WHAT IS A GATE VALVE USED FOR?

A gate valve is commonly used for isolation duties within potable water, wastewater, sewage and fire main applications. They may be used during maintenance tasks and repair works, as well as being deployed in new installations.

There are many different types of gate valves to suit different applications. Some of the most common designs include wedge gate valves, parallel gate valves, knife gate valves, and rising/non-rising stem gate valves. Generally speaking, you can classify gate valves in three different ways:

• According to the disk type - e.g. taper wedge vs flexible vs split/parallel disk gate valves
• According to stem movement - rising stem vs non-rising stem gate valves
• According to bonnet joint - screwed vs bolted vs welded

The best type to deploy will very much depend on what the gate valve is used for. For example, metal seat valves use a non-ferrous metal face, making them ideally suited to wastewater and sewage applications. When isolating water and clean neutral fluids, resilient seated gate valves provide the ideal solution and work using a rubber encapsulated wedge. Meanwhile, knife gate valves are ideal for handling dense fluids and dry bulk solids. Most gate valves deployed in the waterworks industry have non-rising stems, also referred to as inside screw, meaning the stem remains within the body of the valve.

T-T Flow offers a wide variety of gate valves designed to British and European Standard, with many different options to suit differing applications.

For more information or to discuss your requirements, speak to our expert team on +44 (0)1630 647200.

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