Water gate valve manufacturers tell you: what is the difference between cut-off valves and gate valves.
Globe valves, gate valves, butterfly valves, check valves and ball valves produced by water gate valve manufacturers are indispensable control components in various piping systems. They are different in appearance, structure and even functional purposes, but the globe valve and gate valve have some similarities in appearance, and at the same time have the function of truncation in the pipeline, so many people who do not contact the two are easy to confuse the two. In fact, if you look carefully, the difference between globe valves and gate valves is quite big.
Next, the water gate valve manufacturer will introduce the difference between the globe valve and the gate valve.
First of all, water gate valve manufacturers talk about the difference between the two in the structure：
Gate valve can rely on the medium pressure tightly sealed with the sealing surface, so as to achieve the effect of no leakage. When opening and closing, the valve core and the valve seat sealing surface always contact and rub each other, so the sealing surface is easy to wear. When the gate valve is close to closing, the pressure difference between front and rear of the pipeline is great, which makes the sealing surface wear more serious.
The structure of the gate valve will be more complex than the globe valve. From the appearance point of view, the same caliber, the gate valve is higher than the globe valve, and the globe valve is longer than the gate valve. In addition, the gate valve has bright rod and dark rod. Globe valves are not available.
Secondly, water gate valve manufacturers talk about the difference between the two in terms of principle：
When the globe valve is opened and closed, it is the rising stem type, that is to say, it rotates the handwheel and the handwheel will follow the stem to do the rotation and rise and fall movement. The gate valve is to turn the handwheel, so that the valve stem to do lifting movement, the position of the handwheel itself unchanged. Flow rates vary. Gate valves require full opening or full closing, while globe valves do not. The globe valve has specified inlet and outlet directions; Gate valves have no inlet/outlet direction requirements.
In addition, the gate valve only fully open or fully closed two states, the gate opening and closing stroke is large, opening and closing time is long. The disc movement stroke of the globe valve is much smaller, and the disc of the globe valve can stop at a certain place in the movement, and do the flow regulation. The gate valve can only be used for truncation, no other functions.
Moreover, water gate valve manufacturers talk about the difference between the two in terms of performance：
Globe valve can be used for truncation, can be used for flow regulation. The fluid resistance of the globe valve is relatively large, and it is more laborious when opening and closing, but because the distance between the valve plate and the sealing surface is short, the opening and closing stroke is short.
Because the gate valve can only be fully open and fully closed, when it is fully open, the flow resistance of the medium in the valve body channel is almost 0, so the opening and closing of the gate valve will be very labor saving, but the distance between the gate plate and the sealing surface is far, and the opening and closing time is long.
Finally, water gate valve manufacturers talk about the differences in installation and flow direction：
Gate valve flow in two directions the effect is the same, there is no import and export direction of the installation requirements, medium can be two-way circulation. The globe valve needs to be installed in strict accordance with the direction of the arrow identification of the valve body. There is also a clear stipulation on the import and export direction of the globe valve. The flow direction of the globe valve is all from top to bottom.
The globe valve is low into high, from the outside there is obvious pipeline is not a phase horizontal line. The gate valve channel is in a horizontal line. Gate valves have greater travel than globe valves.
From the point of view of flow resistance, when fully open, the gate valve flow resistance is small and the load check valve flow resistance is large. The flow resistance coefficient of ordinary gate valve is about 0.08~0.12, the opening and closing force is small, and the medium can flow in two directions. The flow resistance of ordinary globe valves is 3-5 times that of gate valves. The valve core of the globe valve will contact the sealing surface when it is completely closed, so the wear of the sealing surface is very small. Due to the large flow force, the globe valve of the actuator should pay attention to the adjustment of the torque control mechanism.
There are two ways to install the globe valve, one is that the medium can enter from the lower part of the spool, the advantage is that when the valve is closed, the packing is not subject to pressure, can prolong the service life of the packing, and can be replaced in the case of pressure in the pipeline before the valve, the packing work; The disadvantage is that the driving torque of the valve is large, which is about 1 times the flow into the upper part, and the axial force of the valve stem is large, and the valve stem is easy to bend. So this way is generally only applicable to small caliber globe valve (DN50 below), DN200 or more of the globe valve are selected from the above medium into the way. (Electric globe valve is generally the medium from the top into the way.) The disadvantage of medium entering from above is just the opposite of entering from below.