Rising Stem Gate Valve VS Non-Rising Stem Gate Valve: A Detailed Comparison

Rising Stem Gate Valve VS Non-Rising Stem Gate Valve

Understanding the differences between the two types of gate valves can be confusing, but becoming more familiar with them is essential knowledge when deciding which valve to use in certain applications.

Rising stem gate valves and non-rising valves have benefits and drawbacks; knowing they compare before installation is the key.

In this article, we’ll delve into the detailed comparison between these two gate valves and provide a solid foundation for making an informed decision about which one to use.

Plus, you never know when that kind of knowledge might come in handy.

What is a Rising Stem Gate Valve?

A rising stem gate valve is an important part of our industrial infrastructure. It’s a device used to open and close the flow of liquid or gas passing through pipelines.

It has a thread external to the handwheel and bonnet, which means it “rises” when opened, allowing for an easy visual inspection of whether it is open or closed.

The handwheel operates two threaded wedge-shaped pieces connected to an internal rod, creating the pipeline’s opening or closing action.

Simply put, this system allows us to regulate pipeline pressure, flow and safety effectively.

Rising Stem Gate Valve Construction and Working

Rising stem gate valves are typically constructed with bronze or cast iron bodies, steel bonnets, brass stems, and either metal or rubber seals.

The basic function of a rising stem gate valve is to control the flow of various fluids in a system.

When the handle on the valve is turned clockwise, it moves up (or “rises”) along with the disc inside the valve body, which reduces the opening size for fluid flow, ultimately closing off the flow completely when turned all the way.

When opened counterclockwise, however, it lowers down with its attached disc and opens up an increased size opening for fluid to pass through.

Maintenance of Rising Stem Gate Valve

The maintenance requirements for rising stem gate valves depend on their type (e.g., Bronze vs Cast Iron) and specific application conditions (e.g., pressure, temperature).

Generally speaking, preventive maintenance should be performed regularly to ensure that your valves remain in optimal condition and that any kind of corrosion or wear can be identified quickly before it becomes a problem.

In addition to regular maintenance checks, replace any seals that may have become damaged due to wear and tear to maintain good performance levels and avoid potential leaks/damage in your system.

Applications Of Rising Stem Gate Valve

Rising stem gate valves are used in many industrial applications, including waterworks systems, oil & gas operations, power plants, and chemical plants.

Waterworks Systems, Oil and Gas Operations, and Chemical Plants

  • These valves have an enclosed wedge that rises along the threaded stem when the handle is turned on or off.
  • This ensures that workers can easily see whether or not the valve is open without going into the pipeline itself.
  • Additionally, rising stem gate valves are relatively easy to maintain since their wedges can be replaced without needing to remove from their pipes.

What is Non-Rising Stem Gate Valve?

A Non-Rising Stem Gate Valve is a type of valve that regulates the flow of liquids, gases, and other fluids.

Its unique outside stem, which moves up and down along with the opening or closing of the valve gate, allows for more efficient operation and maintenance while saving space.

This outside stem attaches to a rotary stem inside the valve chamber, allowing it to open or close through simple twisting movements, requiring less effort than most available valves.

Non-Rising Stem Gate Valves are commonly used in industrial equipment and water lines around homes and businesses.

Non-Rising Stem Gate Valve Construction and Working

A non-rising stem gate valve consists of three main components: the body, bonnet, and stem. The body forms the valve’s frame and contains two openings for fluid flow, one at each end.

Inside the body is a wedge-shaped disc that fits into a groove inside the bonnet.

As the stem is turned clockwise, it lowers the disc into the groove, blocking the flow of liquid or gas through the pipe.

To open it again, turn it counterclockwise, which raises the disc from its groove, allowing liquid or gas to pass through once more.  

Maintenance of Non-Rising Stem Gate Valve

Due to their simple design and operation, non-rising stem gate valves require minimal maintenance compared to other valves.

However, they should still be regularly inspected for damage or wear due to corrosion or vibration caused by pressure changes in pipes that carry pressurized fluids such as water or steam systems.

If any parts become worn out, they should be replaced promptly to ensure they continue performing efficiently without compromising safety standards.

Applications Of Non-Rising Stem Gate Valve

Non-rising stem gate valves have numerous applications ranging from industrial piping systems such as oil refineries, chemical plants, power plants, water treatment plants, etc., to commercial buildings.

Oil Refineries, Chemical Plants, and Powerplant

  • Due to its durability, a non-rising stem gate valve is a common choice for oil refineries and chemical plants.
  • This type of valve has a threaded stem, making it suitable for high-pressure and temperature applications.
  • Additionally, the packing box design allows easy maintenance. Workers can make adjustments quickly without replacing any parts.
  • Non-rising stem gate valves are also well suited for corrosive materials since they have no exposed threads that are vulnerable to corrosion.

Main Differences between Rising Stem Gate Valve and Non-Rising Stem Gate Valve

  1. The stem of the rising stem gate valve is attached to the disc at the top, while in a non-rising stem valve, the stem is connected to the disc at the bottom.
  2. The construction of a rising stem gate valve is such that the height of its stem increases as it opens and decreases as it closes, while the stem height of a non-rising stem valve remains constant throughout its operation.
  3. Due to its complex construction, the rising stem gate valve is more expensive than the non-rising stem gate valve.
  4. Rising stem gate valves require more effort to open and close than non-rising stem valves, as they must be manually turned to move the stem.
  5. Since the stem of a rising stem gate valve is visible from the outside, it indicates its position (open or closed) to the operator, while this is not possible with a non-rising stem valve.
  6. Non-rising stem gate valves are more prone to leakage than rising ones, as the former has a seal between its body and bonnet.
  7. Non-rising stem gate valves are better for applications requiring frequent opening and closing than rising ones.
  8. Rising stem gate valves are better suited for applications requiring more precise flow rate control than non-rising stem gate valves.
  9. Rising stem gate valves are better suited for applications where the valve must be operated remotely, while non-rising stem gate valves work best when operated manually.

Video – Piping Engineering : Gate Valve – Difference Between Rising Stem and Non-Rising Stem Gate Valve

Which One is Better?

The choice of a rising stem gate valve or a non-rising stem gate valve depends on the application and flow control requirements.

The rising stem gate valve is better if precise flow rate control is required.

On the other hand, if frequent opening and closing are needed, then the non-rising stem gate valve will be more suitable.

Moreover, the rising stem gate valve should be preferred if the remote operation is necessary.

Ultimately, it’s up to the user to decide which valve will be better for their application.

Conclusion:

Both rising stem gate valves and non-rising stem gate valves have their respective merits, making them both suitable for different applications.

A detailed comparison can help you decide which type of valve will be the best fit for your needs.

In any case, it’s important to remember that correct maintenance and operation are essential for the safe and reliable performance of the valve.

Both types of valves have unique advantages and should be chosen according to the specific needs of your application.

With proper installation and maintenance, they can provide reliable flow control for many years to come.

If you are still confused about choosing between the two discussed gate valves, you can reach out to our professionals at INOXCN.

We can help you choose the right one for your project and will deliver it to your doorstep.

Our team ensures you get the right product at a better price with a fast turnaround time.

Contact us now to get help or a free quote!

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