Electric flange gate valve overview:
The electric flange valve has a larger working force than the electric valve. The electric valve can be adjusted in speed, simple in structure and easy to maintain. Due to the cushioning characteristics of the gas itself, it is not easy to be damaged due to jamming, but it must have a gas source. Its control system is also more complex than electric valves.
The electric flange gate valve is responsive, safe and reliable. Many manufacturers with high control requirements set up a compressed air station for pneumatic instrument control components. Electric is to electricity. And a device that can control its flow.
First, what is an electric valve
The electric valve is simply an electric actuator that controls the valve to open and close the valve. It can be divided into upper and lower parts, the upper part is the electric actuator and the lower part is the valve.
There are two kinds of electric valves, one is the angular stroke electric valve: the electric actuator with the angular stroke is used with the valve of the angular stroke to realize the 90 degree internal rotation control of the pipe fluid on and off; the other is the linear electric valve: The straight-stroke electric actuator is used with a straight-stroke valve to achieve fluid on and off of the valve on-board action control. Usually used on a highly automated device.
Second, the principle of electric valve operation
The electric valve is usually connected by an electric actuator and a valve, and becomes an electric valve after installation and debugging. The electric valve uses electric energy as power to connect the electric actuator to drive the valve to realize the switching and regulating action of the valve. Thereby achieving the switching or regulating purpose of the pipeline medium.
The solenoid valve is a kind of electric valve; the magnetic field generated by the electromagnetic coil is used to pull the valve core, thereby changing the opening and closing of the valve body, the coil is de-energized, and the valve core is returned by the pressure of the spring.
Third, the use of electric valves
Electric valve: Analog adjustment for pipe media flow in liquid, gas and wind systems, is AI control. In the control of large valves and wind systems, electric valves can also be used for two-position switch control.
Electric valve: It can have AI feedback signal, which can be controlled by DO or AO. It is more common in large pipes and dampers.
1. Switch form:
The drive of the electric valve is generally driven by a motor. It takes a certain amount of time to simulate the opening or closing action, and can be adjusted.
2. Nature of work:
The drive of the electric valve is generally a motor, which is more resistant to voltage shock. The solenoid valve is fast open and fast closed. It is generally used in small flow and small pressure, and the electric switch is required in the place where the switching frequency is large. The opening of the electric valve can be controlled. The state has open, closed, half open and half closed, which can control the flow of the medium in the pipeline and the solenoid valve can not meet this requirement.
3. Applicable process:
Electric valves are generally used for adjustment and also have a switching quantity, such as: fan coil end.
Fourth, the specific analysis of electric flange gate valve
With the continuous development of science and technology, China's electric valve product market is also developing towards high-tech content, high parameters, strong corrosion resistance and high life. According to the analysis of electric valve technology at home and abroad and the analysis of the demand of electric valve market at home and abroad, the high-tech development trend and investment direction of industrial electric valve and electric valve industry in various industries in recent years are studied, as follows:
1. Valves for oil and gas wellhead devices
The valves for oil and gas wellheads are mainly single or double gates conforming to the US API6A standard, forged steel parallel gate valves with diversion holes or non-drainage holes, mud valves, angle throttle valves, and oilfield-specific parallel Regulating valve, oilfield-specific straight-through check valve, water injection, polymer-specific parallel gate valve, clamp-type parallel gate valve, pilot-operated safety valve and check valve.
The nominal pressure levels of electric valves for oil and gas wellheads are API2000psi, 3000psi, 5000psi, 10000psi, 15000psi, 20,000psi; nominal diameter is DN46~228mm (113/16in~9in); temperature grade is K(-60~182°C ), L (-42 ~ 182 ° C), P (-29 ~ 182 ° C), R (room temperature), S (-18 ~ 166 ° C), T (-18 ~ 182 ° C), U (-18 ~ 121 ° C ), V (2~121 °C); material requirements are AA, BB, CC, DD, EE, FF, HH; material performance requirements are 36K, 45K, 60K, 75K; product technical requirements according to PSL1 (product specification level 1) , PSL2 (Product Specification Level 2), PSL3 (Product Specification Level 3), PSL4 (Product Specification Level 4).
2. Valves for oil and gas long-distance pipelines
The valves for oil and natural gas long-distance pipelines are mainly single or double gates complying with the US API6D standard, slab gate valves with diversion holes or non-drainage holes; forged steel or cast steel three-body, top-mounted or all-welded Fixed ball valve; oil seal or pressure balanced plug valve; swing or butterfly check valve, ball check valve; pig valve.
The nominal pressure levels of these electric valves are CL150 (PN2.0MPa), CL300 (PN5.0MPa), CL400 (PN6.4MPa), CL600 (PN10.0MPa), CL900 (PN15.0MPa), CL1500 (PN25.0MPa), CL2500 (PN42.0MPa); nominal diameter is DN50~1500mm (2in~60in); fire test technical requirements are according to ISO10497; electric valve pressure test is according to ISO5208.
3. Nuclear power valve
The electric valve for nuclear power has higher technical characteristics and requirements than the electric valve for conventional large-scale thermal power stations. Valves generally have gate valves, globe valves, check valves, butterfly valves, safety valves, main steam isolation valves, ball valves, diaphragm valves, pressure reducing valves and control valves; the highest technical parameters of representative electric valves are: maximum diameter DN1200mm (core 3 butterfly valve), DN800mm (core 2 primary steam isolation valve), DN350mm (core 1 primary circuit gate valve); maximum pressure: about 1500 pounds; maximum temperature: about 350 ° C; medium: coolant (borated water) and the like. Requirements for the production of nuclear-grade electric valve products: usually according to the nuclear industry standard EJ, the United States ASME, IEEE standards and French pressurized water reactor nuclear island machinery and equipment design and construction rules RCC-M.
Fifth, the specific types and parameters of the development of valves for nuclear power
a hydraulic drive gate valve:
The valve pushes the piston to open or close by means of its own pressure water. The nominal diameter of the valve: DN350, 400mm; working pressure: PN17.5MPa; working temperature: 315 °C.
b fully enclosed electric gate valve:
The valve should be equipped with a special screen-closed motor to open and close the shutter through an inner planetary reduction mechanism that is immersed in water. The valve has a nominal diameter: DN100~800mm; working pressure: PN2.5~45.0MPa; working temperature: 200~500°C.
Note: The advantages of the above two non-filled gate valves: no packing seal, avoiding external leaks and reducing energy consumption. Disadvantages: complex structure and high cost.
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