Gate valves are an important component in many industrial applications. Its ability to provide reliable shutoff and control of fluid flow makes it suitable for such operations. As the name suggests, it acts like a Gate. This kind of valve offers a complete shutoff for the water flow, through the ducting process. Best suitable for isolating sections of the pipe, if there is any repair, meter changes, or whenever you need. They are useful for both commercial and domestic purposes. Gate valves are mainly used in industries like chemical processing, power plants, oil and gas industries, and water treatment plants. Gate valves are designed to provide a tight seal and used in areas, where complete shutoff is needed. Based on their stem design, it has two main types:

·       Rising stem Gate valves

·       Non-rising stem gate valves

Rising stem and non-rising stem gate valves are the commonly used Gate valves. Let us check the difference between them and their applications.

What is a Rising Stem Gate Valve?

Rising stem gate valves, which are also known as the ‘Outside screw and Yoke valves (OS & Y), feature a threaded stem that rises or lowers when the valve is operated. The stem is attached to the gate. When the valve is opened, the stem will rise out of the valve body, making it visible. Vice versa, when the valve is closed, the stem will lower back into the valve body.

Main Characteristics

·       You can see!

One of the main advantages of rising stem gate valves is that the valve position is visible. The rising stem indicates whether the valve is open or closed, which is easy and useful for monitoring and maintenance.

·       Rising stem gate valves are way more durable as stem threads are not exposed to the fluid flow, which will eventually reduce the risk of wear and corrosion

·       Maintenance: Maintenance and lubrication of the stem are easier because the stem is accessible when the valve is open.

Advantages

·       The rising stem gate enhances safety and monitoring, as it indicates the clear position of the valve, during its operations.

·       It reduces the wear and corrosion. The stem threads are not exposed to the flow medium, so it reduces the risk of damage and extends the valve's lifespan.

·       It is easy to maintain. Maintenance tasks like lubrication, which is more straightforward because the stem is exposed when the valve opens.

Commercial applications:

Water Supply Systems: Rising stem Gate valves are used in water treatment plants, water distribution networks, irrigation systems, etc.

Oil and Gas: they are more suitable for pipelines and processing facilities where monitoring is crucial.

Chemical Processing: This kind of industry requires robust and reliable shutoff, so it is ideal to use Rising stem gate valves.

Moreover, rising stem gate valves are suitable for applications where space is not a constraint and where it requires a clear visual indication of the valve position.

What is a Non-Rising Stem Gate Valve?

Non-rising stem gate valves, which are also known as the ‘inside screw gate valves’, feature a threaded stem that will rotate, either to lift or to lower the gate. But the stem itself will not move up or down. Instead of that, the gate moves along the threaded stem within the valve body.

Main Characteristics

·       This has got a compact design. They are more suitable for installations where space is limited.

·       The stem has an enclosed system within the valve body, which protects it from any kinds of environmental elements or any potential damage.

·       Since the stem does not rise or lower by itself, there is an external indicator or a handwheel that will mark the valve’s position and act as a physical position indicator.

Advantages

·       They are space efficient due to their compactable design, which makes them ideal for any confined spaces where vertical space area is limited.

·       The enclosed stem design enables protection against any kind of specks of dirt, debris, or environmental factors, that can affect the valve functions and system operations. So, it reduces the risk of operational issues.

·       Non-rising stem gate valves are very cost-efficient as they have a simple design and fewer materials are required.

Commercial Applications

·       Non-rising stem gate valves are suitable for applications where the space is limited. Also, where the valve requires protection against environmental pollutants and other elements like dirt, dust, etc.

·       Underground Installations: they are useful in water and sewage systems where there is limited space and a higher chance of getting polluted due to environmental factors.

·       Suitable for industrial plants such as chemical, petrochemical, and power plants where compact design is necessary. Also requires protection against any external elements.

·       Suitable for building services like HVAC and plumbing systems whether it is a large commercial space or any residential buildings.

The main Difference and Comparison

When you choose between rising stem and non-rising stem gate valves, several factors have to be taken into consideration like:

·       Space: when the vertical space is limited, a non-rising stem gate valve will be more suitable.

·       Visual indication: If the application requires a clear visual indication of the valve’s position, then go for a rising stem gate valve as it is the best choice.

·       Where environmental conditions affect the working of the machine or installations are done in areas that are exposed to dust, dirt, debris, or harsh weather conditions, it is best advisable to go for a non-rising stem gate valve as it provides better protection from such elements.

·       Rising stem gate valves are more suitable for applications where easy and accessible maintenance is required or lubrication is necessary.

Conclusion

Knowing the main differences between rising stem and non-rising stem gate valves is very important for the selection of the right valve depending on the specific applications. Rising stem gate valves offer a clear indication of the valve position, and they are more durable in harsh environmental conditions but they require more vertical space for the installation and working. However non-rising stem gate valves are more compactable and are protected from environmental substances, which makes them ideal for confined spaces and they are suitable for underground installations. So, based on the requirements of the application, considering the space, and environmental conditions, choosing the appropriate gate valve can ensure reliable and efficient operation, for maintaining system performance and ensuring safety.