Globe valve is explained along with its basics, definition, parts, working principles, diagram, design, advantages, disadvantages, etc.
Let’s explore Globe Valve!
Before going to the globe valve, let’s try to understand the valve first. As we know, the fluid’s first and foremost property is to flow, and when it comes to regulating, controlling, or directing it, then one of the things that come into play is a valve. Valves can regulate or control a fluid’s flow.
They perform those functions by,
These are mainly the fittings, which have their own set of descriptions. The core word was derived from the Latin word ‘valva,’ which signifies the door’s moving part, and from vovere, which means to turn or roll.
Here, we are going to discuss the globe valve that is being widely used. A Globe valve holds a prominent place in obstructing or controlling the flow of a fluid.
In layman’s language, a globe valve is a valve that acts on the principle of linear motion, which is used to start, stop, and regulate fluid flow.
The globe valve optimal throttling ability that regulates the flow.
Somehow we wonder why it is called a globe valve?
However, the main internal element in these valves that restricts the flow of fluid is not spherical.
Those parts are more like,
Globe valves are comparatively more restrictive to the flow than other valves, which results in higher pressure drops.
There are different parts of the globe valve that help in its core work. Here we are providing a brief description of all of the parts.
The outer part of the valve is known as a bonnet, and it holds the other core parts of the globe valve.
This part acts as the connector for the disk and valve actuator, which transmits the force explicitly.
This part of the globe valve surrounds the stem in the valve.
The disk is the core part responsible for providing a barrier that blocks or restricts the fluid flow. It moves perpendicular to the seat. When the valve is closed, the disk remains against the seat, which results in plugging the fluid flow, and when it is opened, the disk remains at the top of the seat that helps in passing the liquid.
Globe valve disc is generally three categories,
The ball disk type is used to stop and start fluid flow. Normally, it is widely in low-pressure as well as low-temperature applications.
The needle disk type is better than the ball disc type and used for controlling fluid flow.
The composition disk type is best for shutoff operation.
This part of the valve is essential as it provides all between the bonnet and stem when the disk is rightly pressed. It is tightened with a screw to the valve.
When the globe valve is in operation, there may be a chance of leakage of the fluid from the valve between stem & body.
Here, gland packing is essential which prevents the leakage of the fluid from the stem.
The design of the gloves holds significant importance. There are three major components of the globe valve:
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The core operation involves the rotation of the threaded stem equipped with a valve actuator or handwheel. The fluid flow passes through the Z Shaped path that helps in meeting at the disc head. The whole process is different from other valves, such as gate valves, etc.
Some of the core functionalities of globe valves also depend upon the design of the sealing element. Numerous globe valves can be open with a low number of turns of the stem that produce a more regulated fluid flow.
However, the plug is also used performs sealing element function which is vital for pistons. Plug being an essential part of the globe valve helps in the globe valve’s effective working mechanism. The design of the globe valve keeps it differentiated from other types of valves.
The core working of globe valves is not that complicated, but there are some of the processes that hold massive importance. The whole valve is controlled by an automatic actuator that helps in regulating the flow of the fluid.
Let’s try to look at a globe valve diagram to understand the basic function of the valve.
Globe valve has a disc that works based on two scenarios,
Closing against the flow
Closing with the same flow direction
There are different kinds of globe valves available. Depending on the type of core attributes, the types of globe valve are defined below:
Depending on the type of body, globe valve can be classified into three major types:
This is the most common and simple type of globe valve, which is equipped with a simplistic design.
The whole construction of the valve is quite simple. This construction helps the valve seat to be accessible through the bonnet. The design of this valve makes the installation, manufacturing, and repair quite simplistic.
This type of Globe valve is widely used in those places where pressure drop is not an issue, and throttling is the basic need.
In those places where there is a problem of the high-pressure drop, the Y Type globe valve provides practical help compared to Z-types.
These are the most efficient kinds of globe valves that effectively turn the fluid flow direction by 90 degrees.
Globe valves can also be classified based on body bonnet connection. Below is a brief description of some of them:
Globe valves are widely used for different purposes. Some of the practical applications which are quite important are as follows:
The advantages of a globe valve depend upon the excellent mechanism of the same. The mechanism of regulating the flow through the globe valve massive importance. Here we are providing some of the benefits of using globe valves:
Some disadvantages restrict the productivity of globe valves. Some of them are as follows:
While choosing a valve, it is essential to consider some of the attributes that define the valve’s optimal functions.
The Standard of the valve defines the quality of the valve. This is among the prominent attributes that help in the selection of valves. There are mainly two standards on which these valves are defined:
There are some other standards also which depend on where they are manufactured. The standard requirements are specified according to these, and they are made as per fitment.
API 598 – Valve Inspection and Testing
API STD 624 – Type Testing of Rising Stem Valves Equipped with Graphite Packing for Fugitive Emissions
BS 5152 – Cast Iron globe and globe stop and check valves
BS 5352 – Cast and forged steel gate, globe, check and plug valves, screwed and socket welding ends
BS 1873 – Steel globe valves and stop and check valves, flanged and butt welding ends
API 623 – Steel Globe Valves-Flanged and Butt-welding Ends, Bolted Bonnets
MSS SP 80 – Bronze globe valves
MSS SP 61 – Pressure testing of steel valves
MSS SP 25 – Standard marking system for valves, fittings, flanges & unions
MSS SP 45 – Bypass and drain connections
The valve type is defined based on the process and the function for which it is going to be used. There are different considerations while choosing the type of valve.
This can depend on the need such as
Apart from this, it is also crucial to decide that you need a valve that has seals on both sides or not. When it comes to replacement projects, valve choice only depends on replacing the same type of valve.
One can also get adequate information about different kinds of valves from the catalog of the desired manufacturer.
The size of the valve should be according to the size of the pipe. Globe Valve is widely used for small sizes. Normally, about 10 inches or less, globe valves are used.
It’s relatively easy to install. However, some of the factors should be considered while choosing the valve based on size.
While selecting valves or working concerning fluid flow needs, one of the major considerations is pressure. It is vital to give importance to the pressure class of the valve as it is based upon the piping system.
The manufacturing of valves is a delicate process as it is equipped with different parts.
In addition to these, while choosing the appropriate valve, don’t forget to consider the ambient conditions that play a significant role in the operation.
The above fact shows that globe valves are optimally excellent equipment for automation. The construction of these valves depends upon the manufacturer’s discretion as they keep on using different methods.
The valve is one of the simplest devices or equipment manufactured as a fluid flow controller. Simply it blocks the path or pipe to manage the flow of fluid. You may found it everywhere at each of the places where the fluid flows in any form.
Even it is present in the plumbing system of your house. The core function of the valve is to control the fluidity.
Suppose the valves were not made in this world; think about the consequences you would have gone through. Hefty water bills, no water transportation, and so many scenarios like this where we had to manage things independently. It would have resulted in an inconvenience for everyone.
Therefore, the valve is significantly important for our existence.
A standard globe valve part specification list is showing here, for basic understanding,
This article is all about globe valves. If you want to gain efficient insights about one of the most critical regulatory tools in fluid mechanics, then this article will provide you all. Here you can gain access to the core definitions as well as all the subsidiary information.
The design and working of the globe valve will provide you rooted knowledge about the same. Apart from that, the types, advantages, and disadvantages are the most prominent aspects that help get all-around aspects of the globe valve. Additionally, this excerpt also holds the key areas that should be considered while choosing an efficient valve.
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