Working principle and operation method of globe valve
In the process of production pipes in the coal chemical workshop, globe valves are often used. Let's analyze the working principle and operation of globe valves. Let's take a look today.
A globe valve, also known as shut-off valve, is one of the most widely used valves. The reason why it is so popular is the friction between the sealing surfaces during opening and closing is small, more durable, the opening height is not large, and the manufacturing is easy. Moreover, globe valves are easy to maintain, not only suitable for medium and low pressure, but also suitable for high pressure. The globe valve is a valve sealed by using force, so when the valve is closed, pressure must be applied to the disc to force the sealing surface to not leak.
The working principle of the globe valve: The valve plays an important role in cutting off and throttling the medium in the pipeline. As a very important cut-off valve, the globe valve is sealed by applying torque to the valve stem. The pressure is applied to the valve disc in the axial direction, so that the sealing surface of the valve disc and the sealing surface of the valve seat closely fit together to prevent the medium from leaking along the gap between the sealing surfaces.
The sealing of the globe valve is composed of the valve disc sealing surface and the valve seat sealing surface, and the valve stem drives the valve disc to move vertically along the center line of the valve seat. During the opening and closing process of the globe valve, the opening height is small, easy to adjust the flow, and easy to manufacture and maintain, with a wide range of pressure application.
Compared with gate valve, one of the commonly used cut-off valves in industrial production, from the structural point of view, the globe valve is simpler than the former, which is convenient for manufacturing and maintenance. In terms of service life, the sealing surface of the globe valve is not easy to be worn and scratched. During the opening and closing of the valve, there is no relative sliding between the valve disc and the sealing surface of the seat, so the wear and abrasion of the sealing surface is small, and the service life of the sealing surface is improved. The stroke of the valve disc is small during the full opening or closing process, and its height is smaller than other valves. The disadvantage of the globe valve is that the opening and closing torque is large and it is difficult to achieve rapid opening and closing. Because the flow path in the valve body is relatively tortuous, the fluid flow resistance is large, resulting in a large loss of fluid power in the pipeline.
For globe valves, not only installation and maintenance are required, but also operation.
1. The opening and closing of a globe valve should be stable and not be impacted. For some parts of the high pressure globe valve with shock opening and closing, we should consider that this kind of impact force can not be equal to that of the general globe valve.
2. When the globe valve is fully opened, the handwheel should be reversed a little to tighten the threads tightly to avoid loosening and damage.
3. When the pipeline is initially used, there are many internal dirt. You can open the globe valve slightly, using the high-speed flow of the medium to flush it away, and then gently close it (it cannot be closed quickly or violently to prevent residual impurities from trapping the sealing surface), turn it on again, repeat those many times, flush out the dirt, and then put into normal work.
4. If the globe valve is frequently opened, there may be dirt on the sealing surface. When closing, the above method should also be used to wash it off, and then formally close it. When closing the valve, flush it with the above method, and then formally close it.
5. If the hand wheel or handle is damaged or lost, they should be equipped immediately, and can not be replaced by a live wrench, so as to avoid damage to the valve stem and the opening and closing failure, resulting in an accident in production.
6. Some media cool after the globe valve is closed, so that the valve parts shrink, the operator should close it again at an appropriate time, so as to avoid fine slits remaining on the sealing surface, otherwise, the medium flows through the fine slits at high speed, and it is easy to erode the sealing surface.
7. During operation, if you find that the operation is too laborious, you should analyze the reason. If the packing is too tight, it can be properly relaxed. If the valve stem is skewed, personnel should be notified to repair it. In some globe valves, when the valve is closed, the closing member expands due to heat, which makes it difficult to open; if it must be opened at this time, you can loosen the thread of the valve cover by half to one turn to eliminate the valve stem stress, and then pull the handwheel.
A globe valve, also known as shut-off valve, is one of the most widely used valves. The reason why it is so popular is the friction between the sealing surfaces during opening and closing is small, more durable, the opening height is not large, and the manufacturing is easy. Moreover, globe valves are easy to maintain, not only suitable for medium and low pressure, but also suitable for high pressure. The globe valve is a valve sealed by using force, so when the valve is closed, pressure must be applied to the disc to force the sealing surface to not leak.
The working principle of the globe valve: The valve plays an important role in cutting off and throttling the medium in the pipeline. As a very important cut-off valve, the globe valve is sealed by applying torque to the valve stem. The pressure is applied to the valve disc in the axial direction, so that the sealing surface of the valve disc and the sealing surface of the valve seat closely fit together to prevent the medium from leaking along the gap between the sealing surfaces.
The sealing of the globe valve is composed of the valve disc sealing surface and the valve seat sealing surface, and the valve stem drives the valve disc to move vertically along the center line of the valve seat. During the opening and closing process of the globe valve, the opening height is small, easy to adjust the flow, and easy to manufacture and maintain, with a wide range of pressure application.
Compared with gate valve, one of the commonly used cut-off valves in industrial production, from the structural point of view, the globe valve is simpler than the former, which is convenient for manufacturing and maintenance. In terms of service life, the sealing surface of the globe valve is not easy to be worn and scratched. During the opening and closing of the valve, there is no relative sliding between the valve disc and the sealing surface of the seat, so the wear and abrasion of the sealing surface is small, and the service life of the sealing surface is improved. The stroke of the valve disc is small during the full opening or closing process, and its height is smaller than other valves. The disadvantage of the globe valve is that the opening and closing torque is large and it is difficult to achieve rapid opening and closing. Because the flow path in the valve body is relatively tortuous, the fluid flow resistance is large, resulting in a large loss of fluid power in the pipeline.
For globe valves, not only installation and maintenance are required, but also operation.
1. The opening and closing of a globe valve should be stable and not be impacted. For some parts of the high pressure globe valve with shock opening and closing, we should consider that this kind of impact force can not be equal to that of the general globe valve.
2. When the globe valve is fully opened, the handwheel should be reversed a little to tighten the threads tightly to avoid loosening and damage.
3. When the pipeline is initially used, there are many internal dirt. You can open the globe valve slightly, using the high-speed flow of the medium to flush it away, and then gently close it (it cannot be closed quickly or violently to prevent residual impurities from trapping the sealing surface), turn it on again, repeat those many times, flush out the dirt, and then put into normal work.
4. If the globe valve is frequently opened, there may be dirt on the sealing surface. When closing, the above method should also be used to wash it off, and then formally close it. When closing the valve, flush it with the above method, and then formally close it.
5. If the hand wheel or handle is damaged or lost, they should be equipped immediately, and can not be replaced by a live wrench, so as to avoid damage to the valve stem and the opening and closing failure, resulting in an accident in production.
6. Some media cool after the globe valve is closed, so that the valve parts shrink, the operator should close it again at an appropriate time, so as to avoid fine slits remaining on the sealing surface, otherwise, the medium flows through the fine slits at high speed, and it is easy to erode the sealing surface.
7. During operation, if you find that the operation is too laborious, you should analyze the reason. If the packing is too tight, it can be properly relaxed. If the valve stem is skewed, personnel should be notified to repair it. In some globe valves, when the valve is closed, the closing member expands due to heat, which makes it difficult to open; if it must be opened at this time, you can loosen the thread of the valve cover by half to one turn to eliminate the valve stem stress, and then pull the handwheel.