Electric ball valve and globe valve area
Electric ball valves and stop valves are two common imported electric valves. Both can be used to switch or regulate water, steam, oil, gas and other media. However, there are still certain differences between these two valves. This article will discuss them in detail. Compare and analyze.
1. The imported electric stop valve is composed of an electric device and a stop valve. It has the characteristics of full functions, reliable performance, advanced control system, small size, light weight, easy maintenance and so on. The valve can be controlled with round holes, centralized control, and automatic control. Widely used in electric power, metallurgy, petroleum, chemical industry, papermaking, sewage treatment and other industries.
Main technical parameters of imported electric stop valve
Nominal diameter: DN50-600mm
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, maximum rotation number 60-240 turns, divided into conventional outdoor type, explosion-proof type, Overall adjustment type.
Power supply: Conventional: three-phase 380V (50Hz)
Special: three-phase 660V, 415V (50Hz, 60Hz)
Single phase 220V, 110V (50Hz, 60Hz)
Working environment temperature: -20-60℃ (special order -40-80℃)
Relative humidity: ≤95% (at 25℃)
Protection type: Outdoor type is used in places without flammable, explosive and corrosive media.
Structural features of imported electric stop valves
1. The materials are carefully selected, complying with relevant domestic and foreign standards, with reasonable structure and beautiful appearance.
2. The sealing surface of the valve disc and valve seat is made of 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. The valve stem has been tempered and surface nitrided, and has good corrosion resistance and scratch resistance.
5. Various piping 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, and can be applied to various pressure, temperature and medium working conditions.
7. The inverted seal is made of threaded sealing seat or body surfacing of austenitic stainless steel. The sealing is reliable and the packing can be replaced without stopping the machine. It is convenient and fast and does not affect the operation of the system.
8. Equipped with DZW series multi-rotation electric device, which has a small shell, light weight, full functions, and can be used with a remote computer. An electric device can also be selected according to user requirements. The stop valve is a forced sealing valve with a valve stem. The opening or closing stroke is relatively short and has a very reliable cutting action, making this valve very suitable for cutting off or regulating and throttling media. Therefore, when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from below the valve disc, the resistance that the operating force needs to overcome is the friction between the valve stem and the packing and the thrust generated by the pressure of the medium. The force to close the valve is greater than the force to open the valve, so the valve The diameter of the stem must be large, otherwise the valve stem will bend. Once the valve disc of the stop valve is in the open state, there is no contact between its valve seat and the valve disc sealing surface, and it has a very reliable cutting action. This kind of valve is very suitable for cutting off or regulating media and Use sparingly!
Globe valve has the following advantages:
1. Simple structure, convenient to manufacture and maintain.
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 stop valves are as follows:
1. The fluid resistance is large, and a large force is required when opening and closing.
2. Not suitable for media with particles, high viscosity, and easy coking.
3. Poor adjustment performance.
2. Electric ball valve
The imported electric ball valve is composed of an integrated electric actuator. It is mainly used for two-position cutting and adjustment. The connection between the valve and the actuator adopts a direct connection method. The electric actuator has a built-in servo system. There is no need to install an additional servo amplifier. The operation can be controlled by inputting a 4-20mA signal and a 220VAC power supply. It has the advantages of simple wiring, compact structure, small size, light weight, low resistance, stable and reliable action.
The imported electric ball valve adopts a central structure. During the closing process, the sealing specific pressure between the valve seat and the ball cooler can increase rapidly, thus ensuring reliable sealing of the sealing pair. When the valve is opened, the valve seat and the ball can quickly separate, effectively reducing the operating torque and minimizing the possibility of damage between the valve seat surface and the ball surface.
The working principle of the ball valve is to rotate the valve to open or block the valve. The ball valve has a light switch, small size, can be made into a large diameter, reliable sealing, simple structure, and easy maintenance. The sealing surface and spherical surface are always in a closed state and are not easily eroded by the medium. They are widely used in various industries. High-pressure ball valves are divided into two categories, one is the floating ball type and the other is the fixed ball type.
Ball valves are mainly used to cut off or connect the media in pipelines, and can also be used to regulate and control fluids. Among them, the hard-sealed V-shaped ball valve has a strong connection between its V-shaped ball core and the metal valve seat with hard alloy surfacing. Shearing force, especially suitable for media containing fibers, tiny solid particles, etc. The multi-way ball valve can not only flexibly control the confluence, divergence, and flow direction switching of media on the pipeline, but can 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 a pipe section of the same length.
2. It has simple structure, small size and light weight.
3． Tight. At present, plastic is widely used as the sealing surface material of ball valves, which has good sealing performance and has also been widely used in vacuum systems.
4. It is easy to operate and opens and closes quickly. It only needs to be rotated 90° from fully open to fully closed, which is convenient for long-distance control.
5. It is easy to maintain. The ball valve has a simple structure and the sealing ring is generally movable, making it easy to disassemble and replace.
6． When fully open or fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium. When the medium passes, it will not cause erosion of the valve sealing surface.