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Valves used in various industries are differentiated by the valve type, model, design, and operations. More specifically, they are classified either based on mechanical motion, function, end connections, the actuator used and how they were constructed. But in this article, we are only going to focus on one classification based on the valve construction process – forged steel valves.

Forged steel valves are made by using a forging machine and applying pressure to a metal sheet. This metal is deformed and forged until the desired valve shape and size is obtained.

The process of forging makes the valves more appropriate in high-temperature and high-pressure applications. They are used in industries like oil and gas industries, paper industries, chemical industries, textile industries and more.

So in the following sections, the process of steel forging will be discussed. Followed by types, applications and features of forged steel valves.

Valve Steel Forging Process

A specific combination of materials melted at very high temperatures is required for alloy or steel castings. These metals are molded to construct different kinds of components such as valve bodies, caps, disk and bonnets. Bars and billets (a piece of steel in various shapes that are cut into smaller pieces) are also used in other cast items.

Steel Forging in Valve Parts Construction 1
Source: https://blog.projectmaterials.com/valves/forging-steel-casting/

Forging steel is probably one of the oldest techniques in fabricating steel components. Steel forging starts with a piece of rolled steel that is formed to realign the structure of the grains. This process realigns the initial pattern of the melted metallic mixture into a more linear one.

Following the initial step, steel bars or billets are cut in a specific length. After which they are subjected to high temperature depending on the temperature on which the given steel alloy can be forged. The cut pieces are then put in a press. Where thousand tons of pressure is utilized to crush the steel bar towards the forging dies.

Steel Forging in Valve Parts Construction 2

Source: https://ambicasteels.com/stainless-steel-products/hot-rolled-steel-bars/

Some of the largest valve manufacturers have also done exotic forging and pressing operations to forge large valve bodies. These procedures generate the majority of the valve flow areas in the pressing process. Moreover, it eliminates the extra costs needed to remove these unwanted metals.

Dies Used in Steel Forging

There are two kinds of dies used in forging steel: open-die and closed-die.

Steel Forging in Valve Parts Construction 3

Source: https://www.steelavailable.com/en/open-die-forging-closed-die-forging-whats-difference/
In the open-die process, the geometry and shape of the forged steel valve parts are very close to the desired dimensions. You can read more about the open die forging process here.

While in the closed-die process, the resulting forged steel valve part still needs minimal machining. Because the process constructs parts with extra exterior flash in the valve’s periphery that ought to be removed in another pressing process. After the second pressing operation, the valve part now goes to the post-weld heat treatment if it is still needed. Finally, the part is subjected to final machining to obtain the desired shape.

Check this link out if you want to read more on closed die forging process.

Why Valve Manufacturers Use Steel Forging

But why do some valve manufacturers use steel forging? Here are the reasons why:
Forged steel valve parts have always better quality than the ones produced by the casting process.
The steel forging process is easier to work with when customizing valve parts such as the valve’s body, disc, seat, and others.
Steel forging for valve components is more ideal because the cost of the dies used and the forging process itself is reasonable.
More accurate valve parts with net shape can be produced in the steel forging process using the closed-die method. Lesser machining is done or no second pressing operation at all is needed.

Forged Steel Valve Types and Applications

There are three most popular types of forged steel valves accessible in the market. They are used based on different purposes mostly in industries. These are forged steel check valves, forged steel gate valves, and forged steel globe valves.

These popular forged steel valves are built in compliance with the American Petroleum Institute (API) standard 602. API 602 forged steel valves can be found in every petrochemical plant and refineries in the world. More specifically, forged steel gate valves are the ones mostly used in piping operations in petrochemical industries. This makes finding the best gate valve manufacturers in India crucial.

Aside from these industries, these valves are also used in power plants including chemical plants but in a lesser extent. But why aren’t API 602 forged steel valves not used in chemical plants very often? This is because these valves are more expensive than the other ones.

In some applications, large forged steel valves are considered an excellent choice. When high integrity is required for a valve body, having large forged steel valve components are usually cheaper. This is because cast valve components need a lot of welding repair to make it match the quality of forged steel valves. An example of an application that requires a high-integrity valve body is hydrogen services.
Features of Forged Steel Valves
By the way, you may be wondering why forging is preferred in industries that have greater demands in temperature ranges. This is because forged steel valves are:
More powerful and efficient
Cost-effective
Highly durable than cast valves
Manages effects better than castings
Lasts longer, and
Does not need lubrication

Conclusion

There you go, now you have a basic understanding of what forged steel valves are and how they are made.

To wrap it all up, here are the key takeaways:
Steel forging is one of the oldest procedures in fabricating steel components.
There are two kinds of dies used in forging steel: open-die and closed-die.
Valve manufacturers prefer steel forging because it is cost-effective, makes customizing parts easier, and the components produced have better quality.
There are three most commonly used forged steel valves – forged steel check valves, forged steel gate valves, and forged steel globe valves.
Forged steel valves are found in petrochemical plants, refineries, power plants, and chemical plants.

That’s it. We hope you have learned a lot about forged steel valves in this article!