Three Valves, Three Different Jobs

At first glance, all three appear to perform a similar function: controlling the movement of fluid through a pipeline. However, the way they operate, their internal construction and the applications for which they are best suited can be very different.

Choosing the wrong valve can lead to unnecessary pressure loss, poor flow regulation, premature wear and increased maintenance. Understanding how each valve works is the first step towards making the right selection.

1. Gate Valves – Designed for Isolation

A gate valve uses a gate or wedge that moves vertically inside the valve body.

When the valve is opened, the gate lifts out of the flow path, allowing the fluid to pass through.

When the valve is closed, the gate lowers onto its seating surfaces, stopping the flow.

Because the gate is largely removed from the flow path when fully open, many gate valve designs provide relatively low resistance to flow.

In simple terms:

Gate lifts → Flow passes through → Gate lowers → Flow stops.

Where Are Gate Valves Used?

Gate valves are commonly used where sections of a pipeline or equipment need to be isolated.

Typical applications include:

• Steam distribution systems
• Industrial water pipelines
• Oil and compatible gas services
• Industrial processing plants
• General pipeline isolation

Within the AVS range, Xiamen WCB carbon steel gate valves are available in Class 150 and Class 300 configurations.

What Should You Know About Gate Valves?

Gate valves are generally designed to operate either fully open or fully closed. They are not normally recommended for continuous flow regulation.

When a gate valve operates partially open, the flow passing around the gate can cause vibration, erosion and damage to the seating surfaces. Gate valves also typically require multiple turns of a handwheel to open or close completely.

The key advantage: Reliable isolation with relatively low flow resistance when fully open.

2. Globe Valves – Designed for Flow Regulation

A globe valve uses a disc or plug that moves towards or away from a seat inside the valve body. As the disc moves away from the seat, the opening increases and more fluid can pass through. As the disc moves closer to the seat, the available flow area decreases, restricting the flow.

This operating principle makes globe valves particularly suitable for applications where flow needs to be adjusted or regulated.

In simple terms:

Disc moves → Opening changes → Flow is regulated.

Where Are Globe Valves Used?

Globe valves are widely used in industrial systems requiring controlled flow or shut-off.

Typical applications include:

• Steam systems
• Industrial water systems
• Heating applications
• Process flow regulation
• Industrial plant utilities

Within the AVS range, the ARI STOBU® Fig. 006 is an example of an industrial globe valve.

What Should You Know About Globe Valves?

Globe valves are generally better suited to throttling applications than standard gate or ball valves. Their internal design allows the flow opening to be adjusted progressively.

However, the internal flow path of a conventional globe valve typically creates a greater pressure drop than a fully open gate valve or full-bore ball valve. This additional resistance must be considered when selecting a valve for a particular system.

It is also important to distinguish between a manually operated globe valve and a purpose-designed control valve. Although globe valves can regulate flow, not every model is designed for continuous precision control.

The key advantage: Greater suitability for throttling and flow regulation.

3. Ball Valves – Designed for Quick Shut-Off

A ball valve uses a spherical ball with a hole through its centre. When the hole is aligned with the pipeline, fluid passes through the valve. Turning the ball through 90 degrees moves the opening out of alignment with the pipeline, stopping the flow.

This quarter-turn operation allows ball valves to open and close quickly.

In simple terms:

Ball turns 90° → Flow opens or closes.

Where Are Ball Valves Used?

Ball valves are commonly used for isolation across a variety of industrial applications.

Typical applications include:

• Industrial water systems
• Oil and compatible liquid services
• Compressed-air systems
• Industrial processing
• Equipment and pipeline isolation

Within the AVS range, the Modentic MD84 stainless steel ball valve is an example of a compact industrial ball valve.

What Should You Know About Ball Valves?

Ball valves offer quick operation and can provide low resistance to flow, particularly in full-bore designs. However, standard isolation ball valves are generally not intended for prolonged throttling.

When a conventional ball valve is operated partially open, high-velocity flow can cause wear or damage to the ball and seating surfaces. Specially designed control ball valves are available for regulating applications, but these differ from standard isolation designs.

The key advantage: Fast quarter-turn operation and reliable shut-off when correctly selected.

4. Gate vs Globe vs Ball Valves – The Main Differences

Although all three valve types can stop flow, their operating characteristics are not the same.

These are general operating characteristics. Actual performance depends on the valve design, materials, pressure rating and operating conditions.

5. Choosing the Right Valve for Your Application

There is no single valve type that is ideal for every industrial system. The correct choice depends on the operating requirements and the function the valve needs to perform.

• Does the Valve Need to Isolate or Regulate Flow?

If the primary requirement is to stop or allow flow, a gate valve or ball valve may be suitable. If the application requires regular adjustment of flow, a globe valve may be the better choice.

• How Quickly Must the Valve Operate?

A manually operated ball valve can generally be opened or closed with a quarter-turn. Gate and globe valves usually require multiple turns of a handwheel. This difference can be important where frequent operation or rapid isolation is required.

• How Important Is Pressure Loss?

Pressure loss across a valve can affect the performance and efficiency of a system. A fully open gate valve or full-bore ball valve generally creates less resistance than a conventional globe valve. However, the actual pressure drop depends on the valve's design and flow characteristics.

• What Medium Will Pass Through the Valve?

Steam, water, oil, gases and industrial process fluids all have different requirements. The valve body, internal components, seats and seals must be suitable for the intended medium. For example, a valve suitable for industrial water service is not automatically suitable for high-temperature steam or hazardous chemical applications.

• What Are the Operating Pressure and Temperature?

Every valve has pressure and temperature limitations. The selected valve must be suitable for the actual operating conditions, including the relevant pressure-temperature ratings of its materials and components. A pressure class alone does not establish suitability for every operating temperature.

• How Frequently Will the Valve Be Operated?

A valve that remains open for extended periods and is only closed during maintenance has different operating requirements from one that is adjusted several times each day. The frequency and type of operation should therefore form part of the selection process.

6. What Happens When the Wrong Valve Is Selected?

A valve may fit the pipeline perfectly and still be unsuitable for the application. For example, using a standard gate valve to regulate flow continuously can cause vibration, erosion and damage to the seating surfaces.

• Selecting a conventional globe valve where minimal pressure loss is essential may introduce unnecessary resistance into the system.
• Using a standard ball valve for prolonged throttling can cause seat wear and affect its ability to provide reliable shut-off.

Incorrect valve selection can contribute to:

• Premature wear
• Leakage or poor shut-off
• Excessive pressure loss
• Unstable flow regulation
• Increased maintenance requirements
• Reduced system reliability

This is why selecting a valve involves more than simply matching its nominal size to the pipeline.

A Practical Valve Selection Checklist

Before selecting a gate, globe or ball valve, ask:

• Is the valve required for isolation, regulation or both?
• What medium will flow through the valve?
• What are the operating pressure and temperature?
• How important is pressure loss?
• How frequently will the valve be operated?
• Is quick shut-off required?
• What body, seat and sealing materials are needed?
• What connection type is required?
• Will the valve be manually operated or actuated?
• What maintenance access is available?

The Right Valve Starts with the Application

The basic purpose of a valve may seem simple: control the movement of fluid through a pipeline. The difference lies in how each valve achieves that purpose.

• A gate valve lifts a gate out of the flow path to provide isolation.
• A globe valve adjusts the opening between a disc and seat to regulate flow.
• A ball valve rotates a drilled ball to provide quick opening and closing.

Each design has its own advantages, limitations and applications where it is particularly well suited. Understanding these differences helps ensure that the selected valve supports the performance, reliability and operating requirements of the system.

Allied Valve Specialists supplies industrial isolation and flow-control solutions from established manufacturers, including ARI-Armaturen, Xiamen and Modentic. Our team provides specialist product knowledge and technical support to help customers identify suitable valves for their applications.

Not sure whether your application requires a gate, globe or ball valve? Talk to Allied Valve Specialists about your operating conditions and valve requirements.