Electric Actuated Gate Valve Vs Electric Actuated Globe Valve

Different sealing surfaces

Electric actuated gate valve

When opening and closing, the valve core and the valve seat sealing surface are always in contact and rub against each other, so the sealing surface is easy to wear, especially when the valve is close to the closed state, the pressure difference between the front and back of the valve core is large, and the sealing surface wear is more serious;

The sealing surface of the electric actuated gate valve has a certain self-sealing ability, and its valve core is tightly in contact with the valve seat sealing surface by the medium pressure, to achieve tightness and no leakage. The valve core inclination of the wedge gate valve is generally 3~6 degrees. When the forced closing is excessive or the temperature changes greatly, the valve core is easy to get stuck. Therefore, high-temperature and high-pressure wedge gate valves have taken certain measures to prevent the valve core from getting stuck in the structure.

Electric actuated globe valve

Once the valve disc of the electric actuated globe valve is in the open state, its valve seat and valve disc sealing surface are no longer in contact, so its sealing surface has less mechanical wear, but if the medium contains solid particles, it is easy to damage the sealing surface.

The sealing surface of the electric actuated globe valve must be closed by a forced force to achieve sealing. Under the same caliber, working pressure and the same drive device, the drive torque of the globe valve is 2.5~3.5 times that of the gate valve. This should be noted when adjusting the torque control mechanism of the electric actuated valve. The sealing surfaces of the electric-actuated glove valve only contact each other when it is completely closed. The relative slip between the forced closed valve core and the sealing surface is very small, so the wear of the sealing surface is also very small. The wear of the sealing surface of the electric-actuated globe valve is mostly due to the presence of debris between the valve core and the sealing surface, or due to the loose closing state, causing the medium to be flushed at high speed.

Different structures

The electric-actuated gate valve has a more complex structure than the electric-actuated globe valve, and its height is larger. From the appearance point of view, the electric gate valve is shorter and taller than the electric actuated globe valve. In particular, the rising stem gate valve requires a higher height space, which should be considered when selecting the model under limited installation space.

Different flow resistance

When the electric-actuated gate valve is fully opened, the entire flow channel is straight, and the pressure loss of the medium is minimal. Compared with the electric actuated globe valve, its main advantage is that the fluid flow resistance is small. The flow resistance coefficient of the ordinary electric actuated gate valve is about 0.08~0.12, while the resistance coefficient of the ordinary electric actuated glove valve is about 3.5~4.5. The opening and closing force is small. Electric actuated gate valves are usually suitable for working conditions that do not require frequent opening and closing, and keep the gate fully open or fully closed. They are not ideal for regulation and throttling.

The flow resistance of the electric actuated globe valve is large throughout the entire stroke, the unbalanced force is large, and the required driving force or torque is also much larger accordingly. But it is very suitable for fluid regulation and throttling. For high-speed flowing media, the gate can cause the valve to vibrate when it is partially open, and the vibration may damage the sealing surface of the gate and the valve seat, and throttling will cause the gate to be eroded by the medium.

Different flow directions

When installing the electric actuated globe valve, the medium can enter from the bottom of the valve core or the top. The advantage of the medium entering from the bottom of the valve core is that the packing is not under pressure when the valve is closed, which can extend the service life of the packing, and the packing can be replaced when the pipeline in front of the valve is under pressure. The disadvantage of the medium entering from the bottom of the valve core is that the driving torque of the valve is large, about 1.05~1.08 times that of the medium entering from the top, the axial force on the valve stem is large, and the valve stem is easy to bend. For this reason, the medium entering from the bottom is generally only suitable for small-diameter electric stop valves (below DN50), and electric stop valves above DN200 use the medium flowing from the top. Electric actuated glove valves generally use the medium entering from the top. The disadvantage of the medium entering from the top is just the opposite of the medium entering from the bottom. The flow direction of the electric actuated gate valve is the same when entering from both sides. Compared with the electric actuated gate valve, the advantages of the electric actuated globe valve are simple structure, good sealing performance, and easy manufacturing and maintenance; the disadvantages are large liquid resistance and large opening and closing forces.

Different strokes

The stroke of the electric actuated gate valve is larger than that of the electric actuated glove valve.

Different maintenance procedures

The maintenance of the electric actuated gate valve is not suitable for on-site pipelines, while the valve seat and valve disc of most electric actuated globe valves can be replaced online without removing the entire valve from the pipeline. This is very suitable for occasions where the valve and pipeline are welded together. Of course, there are more differences between electric-actuated gate valves and electric-actuated glove valves. In selection and use, we must distinguish their similarities and differences to avoid mistakes.

The application range of electric actuated globe valves and electric actuate gate valves is determined by their characteristics:

In smaller channels, when better shut-off sealing is required, electric-actuated globe valves are often used;

In steam pipelines and large-diameter water supply pipelines, since the fluid resistance is generally required to be small, electric-actuated gate valves are used;