Specific analysis of electric valves: development and investment trend of electric valves in China

One, the specific analysis of electric valves:
With the continuous development of science and technology, China's electric valve products market is also developing towards high technology content, high parameter, high corrosion resistance and high life expectancy. According to the analysis of electric valve technology at home and abroad and the demand of electric valve market at home and abroad, the development trend and investment direction of industrial electric valve and electric valve industry in recent years are studied.
1. valves for oil and gas wellhead installation
The valve of oil and gas wellhead installation is mainly a single gate or double gate, a parallel gate valve, a mud valve, a angular throttle valve, an oil field special parallel regulating valve, an oil field special direct check valve, a special parallel gate valve for water injection, and a clamps flat, which has a guide hole or no diversion hole in the United States API6A standard. Gate valve, pilot safety valve and check valve.
2. valve for oil and gas long-distance pipeline
The valves for oil and gas long-distance pipeline are the single gate or double gate with the American API6D standard, flat gate valves with diversion holes or no diversion holes; forged steel or cast steel trisomy, upper or all welded fixed ball valve oil seal or pressure balance type cock valve; spin off type or butterfly check valve, ball check valve; pipe clearing valve; Valves and so on.
3. nuclear power valve
The electric valves used in nuclear power plants have higher technical characteristics and requirements than conventional electric valves for large thermal power stations. Valves generally have gate valves, cut-off valves, check valves, butterfly valves, safety valves, main steam isolation valves, ball valves, diaphragm valves, pressure relief valves and control valves, and the highest technical parameters of the representative electric valves are the maximum caliber DN1200mm (core 3 butterfly valve), DN800mm (core 2 main steam isolation valve), and DN350mm (nuclear 1 level main return). Gate valve); maximum pressure: about 1500 LB; maximum temperature: about 350 C; medium: coolant (boronizing water). The requirements for the production of nuclear grade electric valve products are usually according to the nuclear industry standard EJ, American ASME, IEEE standards, and the design and construction rules of the French PWR nuclear island machinery and equipment, RCC-M and so on.

Two: the specific types and parameters of the development of nuclear power valves are as follows:

1. Gate valve without stuffing box: a hydraulic drive gate valve. The valve pushes the piston to open or close with its own pressure water. The nominal diameter of the valve is DN350 and 400mm, the working pressure is PN17.5MPa, and the working temperature is 315 degrees centigrade. B fully enclosed electric gate valve. The valve should adopt a special screen closed motor and make the gate plate open and close through the internal planet gear mechanism that is immersed in water. The valve is nominal diameter: DN100~800mm; working pressure: PN2.5~45.0MPa; working temperature: 200~500 C. Note: the advantages of the above two non stuffing gate valves are: no packing seal, avoiding leakage, and at the same time, reducing energy consumption. Disadvantages: complex structure and high cost.

2. Stop valves for nuclear power: globe valves for auxiliary pipes. The valve is usually of three types, that is, packing stop valve, bellows stop valve and metal diaphragm type globe valve. The valve medium is medium parameter (medium temperature and medium pressure) water and steam; the nominal diameter is DN10~150mm.

3. Butterfly valves for nuclear power: butterfly valves used for cooling systems and conveying air medium in containment. The valve is usually composed of three structures, namely, the coaxial direct connecting butterfly valve, the eccentric type metal seal butterfly valve and the double moving type (the butterfly plate is removed before the slewing) and the metal seal butterfly valve is removed. The valve is nominal diameter: DN less than 2500mm; working pressure: PN < 4.0MPa; working temperature: 100~150 C. In addition, the quick closing butterfly valve used in the air duct system, its nominal diameter: DN400~1200mm is also the development direction. In addition, the safety valve to meet the earthquake requirements is also urgently needed to develop nuclear power electric valves.

Three: marine oil valve

Offshore oil extraction platforms, such as oil extraction, blowout prevention, water injection, gas injection, underwater equipment and so on, need to develop some special electric valves that are resistant to seawater and salt spray corrosion. These electric valves require strong corrosion resistance, anti storm and other unusual external forces, and require reliable sealing, flexible operation and convenient maintenance.

Four: petrochemical and electric power valves

The key of structural adjustment of petrochemical and electric power valve products is to develop products lacking in doors. As follows:

(1) high temperature and high pressure regulating valve used in high temperature and high pressure regulating valve of large thermal power unit, its structure design should be determined according to its flow characteristic and control requirement of working condition, it can be single seat, or double seat or sleeve structure. The nominal diameter of the control valve is DN50~500mm, nominal pressure is less than 42.0MPa, and the service temperature is 510~570 C.

(2) high temperature and high pressure large caliber safety valve is used for steam system with high temperature and high pressure large caliber safety valve, and its design structure can be made of spring type. The key problems to be solved in the design are: setting pressure, return pressure, sealing performance, repeated action stability and fatigue of the electric valve. Its nominal diameter: DN200~400mm; nominal pressure: less than 5.0MPa; maximum service temperature: 570 C

Four: environmental protection valve
The environmental protection system needs to develop electric valves: ceramic sealing rotary valve, PVC plastic valve, large sealed flat gate valve, stainless steel plug valve and so on.

Five: the metallurgical system uses valves in the valve metallurgical system. Because the medium is often powdery and suspended solids, and the temperature is high, the wear resistance, temperature resistance and corrosion resistance of the electric valve are higher.

The specific types and parameters of valve development for metallurgical systems are as follows:

The ash gate valve is used for the ash gate valve in the iron making and ash removal system of the steelworks. The medium of ash removal system is "ash powder", not only