Globe valves and gate valves are the two most common types of valves in industrial plants. Both are designed to make the system run as efficiently and safely as possible. However, contrary to popular belief, these valves are not the same.
These valves have similar valve bodies, but they have their own unique designs and applications.
Globe valve
Globe valves vs gate valves are designed for many applications in several fields, including the oil and gas industry. However, the function of each valve is not the same.
The globe valve is usually used to stop, start and adjust the flow in the pipe. They are composed of a spherical body and a disc. The disc in the globe valve is designed to move up and down from the valve seat. When the valve begins to close, these vertical movements allow the space between the disc and seat to slowly change. This gives the valve a good throttling capability and allows it to adjust the flow in the pipeline.
The flow rate of the globe valve depends on the space between the disc and the seat. The further apart they are, the more liquid will flow through the valve.
The stem of the globe valve is also connected to the bonnet right above the disc to maintain a tight seal when the valve is fully closed. Because of this, compared with other valves, the globe valve is less likely to experience seat leakage.
These valves can double as control valves and are usually used in corrosive, highly viscous media and high pressure and high-temperature systems.
Gate valve
Gate valves are also used in factories in the oil and gas industry. However, they are designed only to start and stop the fluid in the piping system. Unfortunately, they cannot regulate flow.
The structure of the gate valve is also different from that of the globe valve. Instead of a disc, these valves have gate faces that are parallel or wedge-shaped, they are designed with a rising or a non-rising stem. This helps workers understand when the valve is fully open or fully closed.
It is well known that these valves have a lower pressure drop and have little resistance to fluid flow, especially in the fully open position. Most importantly, the gate valve can be set in any directional flow. Globe valves, on the other hand, can’t.
One of the main differences between gate valves and globe valves is how these look. The gate valve structure is much simpler. Most of its internal components are located on the top part of the valve body. When it is opened, its body becomes hollow. This is why there is a little pressure drop. The gate valve can have a rising stem or a non-rising stem.
On the contrary, many globe valve parts are inside the cavity. Since its main purpose is to throttle and provide positive closure, this design allows obstacles to help the globe valve achieve this purpose. This design also allows the flow direction and flow rate to be changed, resulting in a high-pressure drop. This globe has a rising stem.
This gate valve is suitable for applications where a low-pressure drop is critical. This is a multi-directional valve. The globe is best used in applications where massive changes in pressure are not an issue. This valve is unidirectional.
The gate valve is not designed for flow control; it is for the isolation of media. The gate valve cannot handle the strength of the medium flowing in the partially opened state. On the other hand, the globe valve is more of a control valve.
In the gate valve working mechanism, the disc lodges between the seats. Its movement is at the right angle in relation to the media flow. It provides either full flow or no flow at all. If you open the valve, the flow space is as big as the valve cavity with little extra where the stem and the seats are located.
The globe valve disc, on the other hand, moves parallel to the media flow. A full flow means the disc only has to move a little from the seat. Its design allows throttling and tight shutoff.
A fascinating facet of valves is that they may look the same but they can function quite differently. This remains true in the case of gate and globe valves. If you are seeking an industrial valve supplier, you can choose manufacturers Yuanda in China. Contact us now!
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