Differences between Globe Valves and Gate Valves
​Can the globe valve and the gate valve be mixed? Let me introduce the differences between globe valves and gate valves.
Structurally
When selecting models with limited installation space, we should pay attention to the following tips.
The gate valve can rely on the medium pressure in order to tightly close the sealing surface. Then, it can achieve the effect of no leakage. When opening and closing, the sealing surface of the valve core and valve seat always contacts and rubs against each other, making the sealing surface easy to wear. When the gate valve is close to closing, the pressure difference between the front and rear of the pipeline is large, making the sealing surface wear more severe.
The structure of a gate valve is more complex than that of a globe valve. From the appearance, the gate valve is taller than the globe valve under the same caliber. The globe valve is longer than the gate valve. In addition, there are two types of gate valves: rising stem gate valves and non-rising stem gate valves.
The working principle
When the globe valve is opened and closed, it is an upward stem type, which means that when the hand wheel is turned, it will rotate and lift along with the valve stem. Gate valves rotate the hand wheel to cause the valve stem to move up and down, while the hand wheel itself remains in position.
The flow rate varies, and gate valves require full opening or full closing, while globe valves do not. Globe valves have specified inlet and outlet directions, while gate valves do not require inlet and outlet directions.
In addition, the gate valve only has two states: fully open or fully closed. And the opening and closing stroke of the gate plate is large, resulting in a long opening and closing time. The travel of the valve plate of the globe valve is much smaller, and the valve plate of the globe valve can stop at a certain position during movement for flow regulation. The gate valve can only be used for cutting off and has no other functions.
Performance differences
The globe valve can be used for both cut-off and flow regulation purposes. The fluid resistance of the globe valve is relatively high, making it difficult to open and close. However, due to the short distance between the valve plate and the sealing surface, the opening and closing stroke is short.
The gate valve can only be fully opened and fully closed. When fully opened, the medium flow resistance in the valve body channel is almost zero, so the opening and closing of the gate valve will be very laborsaving. However, the distance between the gate plate and the sealing surface is far, and the opening and closing time is long.
Installation and flow direction
The flow direction of the gate valve has the same effect in both directions. There is no requirement for inlet and outlet direction during installation. The medium can flow in both directions. Globe valves need to be installed strictly in accordance with the direction indicated by the arrow on the valve body. There is also a clear regulation regarding the inlet and outlet directions of globe valves. According to the "Three Chemicals" regulations for valves in China, the flow direction of globe valves is always from top to bottom.
The globe valve is low in and high out. From the appearance, there is a clear pipeline that is not on the same level line. The flow path of the gate valve is on a horizontal line. The stroke of the gate valve is larger than that of the globe valve.
From the perspective of flow resistance, the gate valve has a small flow resistance and the load check valve has a large flow resistance when fully open. The flow drag coefficient of ordinary gate valve is about 0.08 to 0.12, and the opening and closing force is small. The medium can flow in two directions. The flow resistance of a regular globe valve is 3 to 5 times that of a gate valve. When opening and closing, it is necessary close to achieving sealing forcibly. The valve core of the globe valve only contacts the sealing surface when it is completely closed, so the wear on the sealing surface is very small.
There are two ways to install globe valves. One is that the medium can enter from below the valve core. The advantage is that the packing is not under pressure when the valve is closed, which can extend the packing.
Structurally
When selecting models with limited installation space, we should pay attention to the following tips.
The gate valve can rely on the medium pressure in order to tightly close the sealing surface. Then, it can achieve the effect of no leakage. When opening and closing, the sealing surface of the valve core and valve seat always contacts and rubs against each other, making the sealing surface easy to wear. When the gate valve is close to closing, the pressure difference between the front and rear of the pipeline is large, making the sealing surface wear more severe.
The structure of a gate valve is more complex than that of a globe valve. From the appearance, the gate valve is taller than the globe valve under the same caliber. The globe valve is longer than the gate valve. In addition, there are two types of gate valves: rising stem gate valves and non-rising stem gate valves.
The working principle
When the globe valve is opened and closed, it is an upward stem type, which means that when the hand wheel is turned, it will rotate and lift along with the valve stem. Gate valves rotate the hand wheel to cause the valve stem to move up and down, while the hand wheel itself remains in position.
The flow rate varies, and gate valves require full opening or full closing, while globe valves do not. Globe valves have specified inlet and outlet directions, while gate valves do not require inlet and outlet directions.
In addition, the gate valve only has two states: fully open or fully closed. And the opening and closing stroke of the gate plate is large, resulting in a long opening and closing time. The travel of the valve plate of the globe valve is much smaller, and the valve plate of the globe valve can stop at a certain position during movement for flow regulation. The gate valve can only be used for cutting off and has no other functions.
Performance differences
The globe valve can be used for both cut-off and flow regulation purposes. The fluid resistance of the globe valve is relatively high, making it difficult to open and close. However, due to the short distance between the valve plate and the sealing surface, the opening and closing stroke is short.
The gate valve can only be fully opened and fully closed. When fully opened, the medium flow resistance in the valve body channel is almost zero, so the opening and closing of the gate valve will be very laborsaving. However, the distance between the gate plate and the sealing surface is far, and the opening and closing time is long.
Installation and flow direction
The flow direction of the gate valve has the same effect in both directions. There is no requirement for inlet and outlet direction during installation. The medium can flow in both directions. Globe valves need to be installed strictly in accordance with the direction indicated by the arrow on the valve body. There is also a clear regulation regarding the inlet and outlet directions of globe valves. According to the "Three Chemicals" regulations for valves in China, the flow direction of globe valves is always from top to bottom.
The globe valve is low in and high out. From the appearance, there is a clear pipeline that is not on the same level line. The flow path of the gate valve is on a horizontal line. The stroke of the gate valve is larger than that of the globe valve.
From the perspective of flow resistance, the gate valve has a small flow resistance and the load check valve has a large flow resistance when fully open. The flow drag coefficient of ordinary gate valve is about 0.08 to 0.12, and the opening and closing force is small. The medium can flow in two directions. The flow resistance of a regular globe valve is 3 to 5 times that of a gate valve. When opening and closing, it is necessary close to achieving sealing forcibly. The valve core of the globe valve only contacts the sealing surface when it is completely closed, so the wear on the sealing surface is very small.
There are two ways to install globe valves. One is that the medium can enter from below the valve core. The advantage is that the packing is not under pressure when the valve is closed, which can extend the packing.
