Structurally

Gate valves can rely on medium pressure to tightly close the sealing surface, thereby achieving the effect of no leakage. When opening and closing, the sealing surface of the valve core and valve seat always come into contact and rub against each other, so the sealing surface is prone to wear. When the gate valve is close, the pressure difference between the front and back of the pipeline is large, which causes more severe wear on the sealing surface.

The structure of a gate valve is more complex than that of a globe valve. In terms of appearance, under the same caliber, the gate valve is higher than the globe valve, and the globe valve is longer than the gate valve. In addition, gate valves can be divided into open stem and concealed stem.

Working Principle

When the globe valve is opened and closed, it is a rising stem type, which means that when the handwheel is turned, it will rotate and lift along with the stem. A gate valve rotates the handwheel to cause the valve stem to move up and down, while keeping the handwheel in its original position.

Different Flow

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 have requirements for inlet and outlet directions.

In addition, gate valves only have two states: fully open or fully closed, and the opening and closing stroke of the gate 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. And gate valves can only be used for cutting off and have no other functions.

Performance Differences

Globe valves can be used for both cut-off and flow regulation purposes. The fluid resistance of the shut-off 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 open and fully closed. When it is fully opened, the flow resistance of the medium in the valve body channel is almost zero, so the opening and closing of the gate valve will be very labor-saving. But the distance between the gate and the sealing surface is far, and the opening and closing time is long.

Installation and Flow Direction

The effect of the gate valve is the same in both directions of flow, and 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 the direction indicated by the arrow on the valve body.

The shut-off valve has a low inlet and high outlet, and from the appearance, there is a clear pipeline that is not on the same horizontal line. The gate valve passage is on a horizontal line. The stroke of a gate valve is larger than that of a globe valve.

Sealing

The sealing surface of the shut-off valve is a small trapezoidal side of the valve core (depending on the shape of the valve core). Once the valve core falls off, it is equivalent to the valve closing (if the pressure difference is large, of course it cannot be tightly closed, but the check effect is still good). Gate valves are sealed by the side of the valve core and gate plate, and the sealing effect is not as good as that of a globe valve. Even if the valve core falls off, it will not be equivalent to the valve closing like a globe valve.