Electric gate valve and the electric globe valve is the high-tech valve product recently. It could help you fluid control automatically. Helping you increase productivity and helping to save time.
1. Different Sealing Surfaces
When the gate valve is opened and closed, the valve core and the sealing surface of the valve seat are always in contact and friction with 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 very large, and the sealing surface is even more worn.
And the globe valve disc once in the open condition, its seat and disc sealing surface, no longer contact, so its sealing surface mechanical wear smaller, but medium if containing solid particles, easy to damage the sealing surface. Gate valve sealing surface has a certain self-sealing ability, its spool pressure by the media closely with the sealing surface of the valve seat, to achieve tight no leakage.
Wedge-shaped gate valve spool slope is generally 3 ~ 6 degrees, when forced to close excessive or large temperature changes in the spool easy to jam. Therefore, high-temperature, high-pressure wedge gate valve, in the structure to take a certain measure to prevent the valve core stuck.
The sealing surface of Globe valve must be forced to close the valve to seal. Under the same caliber, working pressure and the same driving device, the driving torque of globe valve is 2.5 ~ 3.5 times of gate valve. This should be noted when adjusting the torque control mechanism of the electric valve.
Cut-off valve sealing surface, only when completely closed to contact each other, the forced closure of the valve core and the relative slip of the sealing surface is very small, so the wear and tear of the sealing surface is very small. And the cut-off valve sealing surface wear, mostly due to the spool and sealing surface before sundries, or because of the closed state is not strict, resulting in high-speed erosion of the media.
2. The Structure Is Different
The gate valve is shorter and higher than the globe valve, especially the stem gate valve needs higher height space, which should be paid attention to when the installation space is limited.
3. Flow Resistance Is Different
When the gate valve is fully open, the whole flow passage is straight, and the pressure loss of the medium operation is minimal. Compared with the globe valve, the main advantage of the gate valve is that the fluid flow resistance is small. The flow resistance coefficient of the common gate valve is about 0.08 ~ 0.12. The resistance coefficient of common globe valve is about 3.5 ~ 4.5. Small opening and closing force.
Gate valve is usually used, do not need to open and close often, and to keep the gate open or closed, not suitable for regulation, throttle use. For the medium of high-speed flow, when the gate is partially opened, it may cause the valve vibration, which may damage the sealing surface of the gate and the valve seat, and throttling will cause the gate to be eroded by the medium.
And the cut-off valve in the entire journey of the flow resistance is very large, unbalanced force, the driving force or torque required is correspondingly much larger. But it is very suitable for regulating and throttling fluid.
4. Travel Differently
The stroke of the gate valve is greater than that of the globe valve.
5. Flow In Different Directions
Cut-off valve in the installation, the media can enter from the bottom of the spool and from the top into two ways. Medium from the bottom of the valve core into the advantage is when the valve is closed without pressure packing, can extend the life of the packing, and in front of the pipeline pressure, can replace the work of packing. Medium from the bottom of the valve core into the disadvantage is the valve drive torque is larger, about 1.05 ~ 1.08 times into the upper, the valve stem by the axial force, the valve stem easy to bend. To this end, the media from the bottom into the way, generally only suitable for small-bore globe valve (below DN50) , DN200 more than the selection of the media from the top into the way. Electric cut-off valve is generally used from the top of the medium into the way. The disadvantage of the medium entry mode from above is just the opposite of that from below.
The flow direction of the gate valve is the same from both sides. Compared with gate valve, globe valve has the advantages of simple structure, good sealing performance, convenient manufacture and maintenance, and large liquid resistance, opening and closing force.
6. The Maintenance Process Is Different
Gate valve repair is not suitable for on-site piping, and most globe valve seats and discs can be replaced online without removing the entire valve from the line It’s a good fit. Of course, gate valves and globe valves are not the only difference, in the selection and use of their differences and similarities in order to avoid mistakes. The application range of globe and gate valves is determined by their characteristics. In the smaller channel, when the need to have a better sealing off, the use of cut-off valve; in the steam pipeline and large diameter water supply pipeline, because the fluid resistance is generally smaller, the use of gate valve.
Post time: Jul-28-2021