A significant portion of sectors around the world implements the use of gate valves, which utilises a wedge or a disc for blocking and releasing the flow of liquids and gases. Specifically designed for certain operational requirements are the Rising Stem Gate Valve (OS & Y Gate Valve) and Non-Rising Stem Gate Valve (Inside Screw Valve). It is important to know the details & distinctions of stem valves in order to make an correct valve choice for your application.
Rising Stem Gate Valve (OS & Y Gate Valve)
The Rising Stem Gate Valve, also recognized as OS & Y Gate Valve, is equipped with a stem that rotates along the vertical axis with the aid of manual handwheels. Based on the movement which the valve is either opened or closed presents itself clearly as the position of the stem. The pre-ordered location of the stem remains external and does not touch the fluid medium thus preventing damage by corrosive or erosive fluids. It is a multi-turn valve whereby rotation of the handwheel causes the stem and the disc to rotate in such a manner that the flow is either allowed to pass control. This control provides several benefits, including, maintenance ease due to the fact that the outer portion of the stem remains external, there is a lower risk of corrosion occurring, and the stem gives external evidence whether the valve is opened or closed. These valves are extensively utilized in oil & gas industries, chemical processing as well as power generation industries where durability of the equipment and occupational health and safety are the key factors.
Non-Rising Stem Gate Valve (Inside Screw valve)
The other name of the non rising stem gate valve is the Inside Screw Valve. When it is used, the handwheel tends to turn which then causes the valve disc to rotate instead of the stem. As such, this design is more compact as only the internal components move. The Other use of this valve is where there is very limited space as it can be under the ground or in areas where the height is low. Therefore, the compact design is quite useful, however, the disadvantage or the drawback of this is because this compact design makes it more vulnerable to abrasion and corrosion in harsh environments due to the threads being directly exposed to the fluid medium. Also, greater clarity in applications that need to be distinctly observed could be one of the disadvantages due to the lack of visual position indicators. These valves are usually used for applications such as municipal water systems, HVAC systems, and clean fluids applications in which exposure of threaded parts is not an issue.
Differences Between Rising Stem and Non-Rising Stem Gate Valves
When it comes to the installation and environmental requirements, it usually determines the use of Rising Stem Gate or Non-rising stem gate valves. Since the external movement of the stem in the Valve indicates its position, it becomes possible to operate such valves in systems with Limited Operational Visibility. Their performance is also enhanced for corrosive or erosive fluids, as the stem threads are not exposed. On the other hand, Non-rising stem gate valves are more compact in size and can be used in space constrained applications. However, They might get less attention as they don’t control space efficiently, and use considerable amount of thread exposure which can potentiate the valve’s application in erosive or corrosive locations.
Conclusion
Both types of gate valves – Rising Stem or Non Rising Stem – have their unique benefits for specific functional requirements. Due to having better strength, resistance to corrosion and visual position indication, Rising Stem Gate Valves are better suited for severe service applications while Non-Rising Stem Gate Valves are ideal where space is at a premium. Each type of valve is suitable for a range of operational conditions and environments or the other is more suited for the company’s expectations in terms of operation and space usage. Here at Induskart, we supply only the best Rising Stem and Non Rising Stem Gate Valves which are crafted to suit industrial needs and provide optimal service and longevity.
