This paper analyzes the similarities and differences of electric valves, mainly electric globe valves and electric ball valves. If you think the answer is helpful to you, please give a compliment to the American Witton VTON valve!
The difference between electric globe valve and electric ball valve is two common imported electric valves, which can be used to switch or adjust water, steam, oil, gas and other media, but there are still some differences between them. This paper makes a detailed comparison and analysis.
An electric cut-off valve consists of an electric device and a cut-off valve. It has the characteristics of complete functions, reliable performance, advanced control system, small size, light weight and convenient use and maintenance. The valve can be controlled by round hole, centralized control and automatic control. Widely used in electric power, metallurgy, petroleum, chemical industry, paper making, sewage treatment and other industries.
Main technical parameters of electric cut-off valve
Nominal diameter: DN50-600 mm
Nominal pressure: pn1.6-16.0mpa.
Material: cast steel, stainless steel, etc.
Electric device: output torque: 300NM- 1200NM, power station type interface, thrust type interface, torque type interface, output speed: 18-24r/min, 60-240 rpm, divided into conventional outdoor type, flameproof type and integral adjustment type.
Power supply: general: three-phase 380V(50Hz)
Special: three-phase 660V, 4 15V(50Hz, 60Hz)
Single-phase 220v,110v (50hz, 60hz)
Working environment temperature: -20-60℃ (special requirements -40-80℃)
Relative humidity: ≤ 95% (at 25℃)
Protective type: outdoor type is used in places without flammable, explosive and corrosive media.
Structural characteristics of cut-off valve
1, exquisite materials, in line with domestic and foreign standards, reasonable structure and beautiful shape.
2. The sealing surfaces of disc and valve seat adopt iron-based alloy surfacing or stellite-cobalt-based hard alloy surfacing, which has good wear resistance, high temperature resistance, corrosion resistance, scratch resistance and long service life.
4. After tempering and surface nitriding, the valve stem has good corrosion resistance and scratch resistance.
5. Various pipeline flange standards and flange sealing surface types can be adopted to meet various engineering needs and user requirements.
6. The valve body has a complete range of materials, and the packing and gasket can be reasonably selected according to the actual working conditions or user requirements, which is suitable for various pressure, temperature and medium working conditions.
7. Inverted seal adopts threaded sealing seat or valve body surfacing austenitic stainless steel, which has reliable performance, convenient and quick replacement of packing without stopping, and does not affect the system operation.
8. It is equipped with DZW series multi-rotating electric devices, with small shell, light weight and full functions, which can be used in conjunction with remote computers. Electric devices can also be selected according to user requirements. Cut-off valve is a kind of forced sealing valve, the opening or closing stroke of the valve stem is relatively short, and it has a very good cutting effect, which makes it very suitable for cutting off or regulating media and throttling. Therefore, when the valve is closed, pressure must be applied to the disc to force the sealing surface not to leak. When the medium enters the valve from below the disc, the resistance to be overcome by the operating force is the friction between the valve stem and the packing and the thrust generated by the medium pressure. The force to close the valve is greater than the force to open the valve, so the diameter of the valve stem should be larger, otherwise the valve stem will bend. Once the disc of the cut-off valve is in the open state, its valve seat and the sealing surface of the disc will no longer contact, which has a very good cutting effect, so this valve is very suitable for cutting off or adjusting the medium and throttling!
Globe valves have the following advantages:
1, simple structure and convenient manufacture and maintenance.
2, the working stroke is small, and the opening and closing time is short.
3. Good sealing performance, small friction between sealing surfaces and long service life.
The disadvantages of globe valves are as follows:
1, the fluid resistance is large, and the force required for opening and closing is large.
2. Not suitable for media with particles, high viscosity and easy coking.
3. Poor regulation performance.
Second, the electric ball valve
Electric ball valve is composed of electric actuator, which is mainly used for two-position cut-off and adjustment. The valve is directly connected with the actuator, and the electric actuator has a built-in servo system, which can be controlled by inputting 4-20mA signal and 220VAC power supply without additional servo amplifier. It has the advantages of simple connection, compact structure, small volume, light weight, small resistance and stable and reliable action.
Imported electric ball valve adopts central structure. In the process of closing, the sealing pressure between the valve seat and the ball increases rapidly, thus ensuring the reliable sealing of the sealing pair. When the valve is opened, the valve seat can be quickly separated from the ball, effectively reducing the operating torque and minimizing the possibility of damage control between the valve seat surface and the ball.
The working principle of ball valve is to rotate the valve to make it unblocked or blocked. The ball valve switch is light in weight and small in volume, and can be made into a large caliber, easy to seal, simple in structure and convenient to maintain. The sealing surface and spherical surface are often closed, and it is not easy to be corroded by media, so it is widely used in various industries. There are two types of high-pressure ball valves, one is floating ball type, and the other is fixed ball type.
Ball valve is mainly used to cut off or connect the medium in the pipeline, and can also be used to adjust and control the fluid. Among them, the hard-sealed V-shaped ball valve has a strong shear force between its V-shaped ball core and hard-faced cemented carbide metal valve seat, which is especially suitable for media containing fibers and tiny solid particles. The multi-way ball valve can not only flexibly control the confluence, diversion and flow direction switching of the medium in the pipeline, but also close any channel and connect the other two channels.
Has the following advantages:
1. The fluid resistance is small, and its resistance coefficient is equal to that of the same length pipe section.
2. Simple structure, small volume and light weight.
3. compactness. At present, plastic is widely used as the sealing surface material of ball valve, which has good sealing performance and has been widely used in vacuum system.
4. Convenient operation, rapid opening and closing, only 90-degree rotation from full opening to full closing, convenient for remote control.
5. Convenient maintenance, simple ball valve structure, movable sealing ring and convenient disassembly and replacement.
6. When fully opened or closed, the sealing surfaces of the ball and the valve seat are isolated from the medium, and when the medium passes through, it will not cause corrosion of the valve sealing surface.
7. Electric ball valves are widely used, ranging from small diameter to several millimeters to several meters, and from high vacuum to high pressure.
Third, the difference between electric actuators
Imported electric ball valve adopts angular stroke electric actuator, and globe valve adopts straight stroke or multi-rotary electric actuator. Under the same specifications, the ball valve is more cost-effective.
To sum up, the main difference between imported electric ball valves and imported electric globe valves is: 1, and the service temperature is different. Generally, the maximum temperature of imported electric ball valves is 250℃, and the maximum temperature of imported electric globe valves is 550℃. 2. The price cost is different. Under the same specifications, imported electric ball valves are cheaper and more cost-effective; 3. Imported electric globe valves are more wear-resistant, better sealed and generally have a longer service life than imported electric ball valves; 5. Different structural dimensions. The structural length of imported electric globe valve is generally longer than that of imported electric ball valve, which occupies a large space. In the case of limited space, it is suitable to use the American Witton VTON electric ball valve.
The above analysis of the difference between electric ball valve and electric globe valve is only theoretical analysis. When using, it should be selected according to the actual application.