Globe Valves: What Sets Them Apart from Standard Valves?

Introduction

In diverse fluid control applications, not all valves are created equal. While standard valves often suffice for simple on/off functions, some specialised applications demand precise, leak-free flow regulation instruments. Enter the globe valves, offering a level of precision and reliability that surpasses their more common counterparts. But what exactly makes them different from other valve types? Read to learn the inherent characteristics of globe valves, exploring the specific differences that set them apart from other alternatives.

What is a Globe Valve? Definition, Types, and Key Components

A globe valve, also known as a multi-turn valve or a throttle valve, is a type of linear motion valve designed to start, stop, and regulate fluid flow in a controlled manner. These valves belong to a broader family of industrial valves and possess unique features. Furthermore, the term “globe” refers to their spherical body shape, which houses an internal baffle that controls fluid movement.

Globe valves can come in straight-through or angled body designs to suit different piping layouts. They are classified into Y-pattern, Z-type, and angle-type globe valves. These multi-turn valves also have a single seat, though double-seated varieties exist to improve shut-off. Additionally, these valves can be operated using a handwheel or an actuator, or they can even be remotely controlled in automated systems.

Globe valves comprise several key components:

• Body – The main housing of the valve that holds all internal components.
• Bonnet – The upper section that encloses the moving parts, including the stem and disk.
• Disk (Plug) – The moving component that regulates fluid flow.
• Seat – The stationary ring where the disk sits to form a tight seal.
• Stem – Connects the actuator or handwheel to the disk, allowing for movement.
• Handwheel/Actuator – Used to manually or automatically operate the valve.

Some Standard Types of Valves Explained: A Brief Look

Valves are indispensable components in fluid control systems used across a range of industries. Furthermore, they come in several types based on their designs, flow mechanisms, and intended use. Some common types include:

Gate Valves – These valves are designed for on/off service, utilising a gate-like wedge that slides to block or allow flow. They’re known for minimal pressure drop when fully open.

Ball Valves – These valves employ a spherical ball with a bore and provide a quick quarter-turn operation for on/off control. In addition, they are versatile and offer tight shutoff with minimal leakage.

Butterfly Valves – Butterfly valves are lightweight and cost-effective options that feature a rotating disc to regulate flow. They are suitable for large-diameter pipes in large-scale applications.

Solenoid Valves – These are electrically controlled valves that use a solenoid to open or close the valve. However, they are used for automated fluid control.

Check Valves – These are unidirectional valves designed to allow flow in one direction only. They are beneficial as they prevent backflow by automatically closing when reverse flow occurs. Check valves are crucial for protecting pumps, pipelines, and other equipment.

Diaphragm Valves – These valves utilise a flexible diaphragm that moves up and down to control flow. Moreover, they provide reliable sealing and minimise contamination, making them suitable for pharmaceuticals and food processing applications requiring contamination-free operations.

Plug Valves – These valves use a cylindrical or conically tapered plug to allow or restrict fluid flow. They are suitable for slurry applications.

Needle Valves – These valves feature a small, tapered needle-like plunger for fine adjustments of fluid flow.

What Sets Globe Valves Apart from Standard Valves?

While many valve types are used for fluid control, globe valves stand out due to the various unique features they incorporate. Below are the key distinctions between globe valves and standard valves based on multiple aspects:

• Design and Structure

Globe valves are characterised by their globe-shaped body, which is divided by an internal baffle. Furthermore, this complex internal structure with a baffle and a movable disc enhances control over fluid flow.

• Flow Control and Throttling

Globe valves excel in throttling applications because they allow incremental adjustments to fluid flow. Standard valves like gate or ball valves typically function as on/off valves with minimal flow regulation.

• Pressure Drop

Due to their design, throttle valves cause a higher pressure drop compared to standard valves. In addition, the fluid changes direction multiple times as it passes through the valve, leading to resistance and energy loss.

• Sealing Performance

Globe valves provide better sealing capabilities than gate valves, making them ideal for applications where leakage prevention is crucial.

• Maintenance and Durability

Globe valves feature a more complex design than standard valves, which means they require more frequent maintenance. However, their durability in high-pressure and high-temperature conditions makes them a preferred choice for specific applications.

• Actuation Options

Globe valves operate manually using a handwheel or automatically with actuators, such as pneumatic actuators and electric and hydraulic actuators.

A Comparison Table of Globe Valves vs. Standard Valves

Globe Valves or Other Standard Valves: Making the Right Choice

When deciding whether to use a globe valve instead of another standard valve type, various parameters need to be considered. If your system values precision control over minimal pressure drop, go for globe valves. They’re the standard for any application demanding nuanced flow regulation. However, these multi-turn valves are my go-to in high-temperature or corrosive environments. They’ve proven sturdy under extreme conditions. Among the key considerations, look for your flow control requirements, pressure drop sensitivity, and budget and maintenance.

Final Thoughts

Globe valves are worthwhile throttle valves that are distinguished by their unique internal design, precise flow regulation capabilities, superior shutoff, and higher pressure drop. They offer significant advantages in specific industrial applications. Finally, choosing the right valve depends on the particular requirements of the application; a globe valve deserves a top spot on your shortlist.