Globe Valves

Globe Valves Supplier

Youyi is a globe valve manufacturer offering four types of globe valves. Our valve factory in China manufactures cast steel globe valves for low pressure and low pressure applications.
Globe valves are known for their effectiveness in controlling and throttling fluids. Sometimes referred to as a throttle valve, a globe valve functions in three ways: to stop the flow, to start the flow or to throttle the flow.
It has a circular body containing a disc, which is then used as a gate. If maintaining pressure levels or reducing pressure loss is not a priority, but the flow of the medium needs to be controlled, use a globe valve.

What is the purpose of a globe valve?

Also known as control valves, globe valves are used to regulate the flow of media. In addition, the globe valve has a high sealing capacity. This also makes it an excellent device for sealing water. Applications for globe valves include

Fuel piping systems
Turbine seals
Heater drainage systems
Turbine lube oil systems
Chemical feed systems
Water supply systems requiring flow regulation

How do globe valves work?

A tap is a perfect example of how a shut-off valve works. Opening the tap means raising or lowering the valve stem, depending on the design. Water then flows out of the tap. When turned in the other direction, e.g. closed, the raised gate is lowered or the lowered gate is raised.

The number of turns affects the amount of water flowing out of the tap. Similarly, a certain volume of gas or liquid passes through the valve by means of the wheel that controls the valve. A fully open shut-off valve means that the flow rate is at its maximum. On the other hand, a fully closed shut-off valve means that the valve is sealed.

Why choose a shut-off valve?

Good throttling capacity
Can be a closed and open valve
More variants in terms of body design, disc and bonnet attachment styles
Can be a non-return valve

Types of globe valves (by body design)

Shut-off valves are available in three body designs. Each has a unique design suitable for a particular application.
T (Tee) type globe valve
This is the most common design. It has the distinctive feature of a Z-shaped diaphragm with the seat horizontal and perpendicular to the stem.
This position allows for a low flow coefficient but high pressure loss. It is therefore ideally suited to throttling applications where the pressure drop is not relevant.
Angled globe valve
This model is an offshoot of the T-pattern. Instead of the fluid moving in a straight line, it passes through the shut-off valve in a 90° turn. This allows for low flow rates suitable for pulsating flow applications. As a result, it prevents sedimentation.
Y (star) type shut-off valve
In contrast to the first two models with upright stems, the Y (star) model has an inclined 45° stem. This model has a lower pressure drop than the first two models.
When fully open, the medium flows more straightly and therefore has a lower pressure drop. the Y design or Y pattern is more common in applications where dirt needs to be removed or where the valve needs to be open for a long time.

Shut-off valves: purpose and function

A stop valve stops, starts and regulates the flow in a pipeline. The valve is shaped like a sphere and consists of a stem that moves up and down, a disc and a seat. It works by lowering or raising the valve disc by the stem. When the disc is lowered, the flow pattern is closed; if the disc is increased to its maximum value, the flow also operates at its maximum value. If the disc is raised to less than the maximum value, the flow will be regulated in proportion to the vertical disc position. The direction of flow in the shut-off valve changes, resulting in greater resistance and a drop in high pressure.

Features and benefits

Easy to maintain and repair
Good shut-off capability
Shorter stem travel
Wide range of patterns available
Good throttling capacity
Can be used as a shut-off check valve

Considerations when purchasing globe valves

Valve size restrictions
Valve diameters are limited due to the internal pressure of the flowing medium. The globe valve manufacturer limits the size to a nominal pipe size (NPS) of 12 or a nominal diameter (DN) of 300. Beyond these limits, the valve may not open or close easily under pressure.
Valve internals
Valve internals often fail when handling throttling and high pressures in excess of 200 psi. In such cases, it is best to request a special valve internals.
PT Rating
The PT rating is a rating of the highest pressure to temperature ratio associated with the metal material that the valve can handle.
As the temperature increases, the body's ability to handle the pressure decreases. In addition, the seat material and design determine the overall rating.
Most globe valve manufacturing companies use the overall rating specified by ANS, i.e. the body pressure rating at 100°F.
Medium
The type of media is one of the most important considerations when purchasing a globe valve. There are many types of media that may or may not be suitable for certain valve designs.
For example, slurries are not suitable media because they are heavy and contain larger components that may be left behind. These, in turn, can damage the disk. In addition, such viscous materials can create significant pressure drops.
 Materials
The medium flowing into the valve is related to the material used to manufacture the valve. Is the material used resistant to corrosion? What is the concentration of the flowing material? Will it be a flowing media condition? Or will it prevent the media from flowing? The answers to these questions have a direct impact on the service life of the valve.
Complying with industry standards
By following and meeting industry standards, it maintains the integrity of the valve and provides assurance of safety.

Types of disc design globe valves

The disc acts as a door to prevent leakage. However, there are three different types of disks that work well under specific conditions and needs. Choosing the right disk ensures the longevity of the control valve.
Ball and disk shut-off valves
This works well in low pressure and cryogenic applications. It is mainly used as a start/stop mechanism but has a throttling function.
Composing a disc shut-off valve
Better closure means less chance of spillage. With this in mind, a disk with an inserted metal ring should come in handy.
Plug-disc shut-off valves
The conical design ensures better throttling capacity than ball and composite disks.

Types of stopcock with bonnet design

Valves are created in different ways. Some do not have caps, others do. Bonnets act similarly to accessories that can be attached to other internal valve components.
Some designs integrate the bonnet with the body. In contrast, some designs have removable bonnets so that other valve components can be easily exposed for cleaning or maintenance.
Threaded bonnet shut-off valves
Often found in inexpensive globe valves, screws connect the valve body to the bonnet.
Bolted bonnet globe valves
This type uses bolts to attach the bonnet to the body. Considered the most common, the connection between body and bonnet is further enhanced by a gasket. In turn, it is sealed tightly.
Welded bonnet shut-off valve
This type is welded rather than attached by screws or bolts, which makes the valve lighter. However, due to the nature of the connection, maintenance and repairs can be challenging.
Pressure-sealed bonnet globe valves
This type of bonnet is often used for applications requiring high temperatures and pressures. The gasket seal should be very durable as the internal pressure increases, as the body transfers the pressure to the gasket.

Globe valves and gate valves

Globe and gate valves may look similar, but their internal
design determines the uniqueness of the two.
Flow regulation is a common use for globe valves. Admittedly, on/off is also one of its applications. The disc that controls the flow moves up and down from a horizontally placed seat.
Thanks to this design, a throttling movement is possible by partially opening the valve. The larger the space between the seat and the disc, the higher the flow rate. The sealing is further enhanced by the valve stem and cap located above the disc. These valves can also withstand high pressures and temperatures, although they have high pressure losses.
Gate valves, on the other hand, are used as start and stop devices to allow certain liquids and gases to pass through the pipeline. Gate valves should not be used to control the flow of media. Wedge or parallel gates will stop the flow of liquids and gases when in the fully closed position.
Gate valves should not be partially opened as vibrations from the movement of liquids or gases will eventually damage the valve seat. Due to the linear movement of the medium through the gate valve, pressure losses are minimal.

Globe valves and ball valves

Externally, globe valves and ball valves look identical. However, looking at the internal design, it is easy to see that the two valves work differently. The main difference between the two is the way in which each closes.

Ball valves stop the flow through a round but hollow spherical gate called a ball. After a quarter turn, the valve can be opened or closed. A globe valve, on the other hand, has a stem that closes it.

The ball valve seat is located next to two openings at each end. In contrast, most globe valves have the seat perpendicular to the stem. The valve flap or plug rests on the seat to seal the valve.