Specific analysis of electric valves:
With the continuous development of science and technology, the market of electric valve products in China is also developing in the direction of high technology content, high parameters, strong corrosion resistance and long service life. According to the analysis of domestic and foreign electric valve technology and the analysis of domestic and foreign market demand for electric valve, the development trend and investment direction of high and new technology in industrial electric valve and electric valve industry in recent years are studied.
1. Valves for oil and natural gas wellhead installations
Valves for oil and natural gas wellhead installations are mainly single gate or double gate, forged steel parallel gate valves with or without diversion holes, mud valves, angle throttle valves, oil field parallel control valves, oil field through check valves, water injection polymer parallel gate valves and clamp flat valves, which meet the API6A standard of the United States. Sluice valve, pilot safety valve and check valve.
2. Valves for Long-distance Oil and Natural Gas Pipelines
Valves for petroleum and natural gas pipelines are mainly single gate or double gate, flat gate valves with or without diversion holes, oil-sealed or pressure-balanced plug valves for forged or cast steel three-body, mounted or fully welded fixed ball valves, swing or butterfly check valves, through ball check valves, pigging valves, etc. Valves, etc.
3. Nuclear Valves
The technical characteristics and requirements of electric valves for nuclear power plants are higher than those for conventional large-scale thermal power plants. Valves generally have gate valves, globe valves, check valves, butterfly valves, safety valves, main steam isolation valves, ball valves, diaphragm valves, pressure relief valves and control valves; the highest technical parameters of representative electric valves are: maximum diameter DN1200mm (nuclear stage 3 Butterfly valve), DN800mm (nuclear stage 2 main steam isolation valve), DN350mm (nuclear stage 1 main return). Gate valves; Maximum pressure: about 1500 pounds; Maximum temperature: about 350 degrees Celsius; Medium: Coolant (water boride), etc. Requirements for the production of nuclear grade electric valves: usually according to the nuclear industry standards EJ, ASME, IEEE and RCC-M, etc.
II. Specific types and parameters of the development of nuclear power valves are as follows:
(1) Gate valve without packing box: a hydraulic drive gate valve. The valve opens or closes the piston by means of 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 C. B Fully enclosed electric gate valve. The valve shall adopt a special shut-in motor to make the gate open and close through the inner planetary deceleration mechanism for immersion operation. The nominal diameter of the valve is DN100-800mm, the working pressure is PN2.5-45.0MPa, and the working temperature is 200-500 C. Note: The advantages of the above two kinds of non-filler box gate valves are: no filler seal, avoiding leakage point, and reducing energy consumption. Disadvantage: Complex structure and high cost.
(2) Globe Valve for Nuclear Power: Globe Valve for Auxiliary Pipeline. The valve usually has three kinds of structure, i. e. packing type globe valve, bellows type globe valve and metal diaphragm type globe valve. The valve medium is medium parameter (medium temperature, medium pressure) water and steam; nominal diameter: DN10 ~ 150 mm.
(3) Butterfly valves for nuclear power: butterfly valves for cooling systems and systems for conveying air media in containment. The valve usually has three kinds of structure, namely coaxial direct lining butterfly valve, eccentric metal seal butterfly valve and double-acting metal seal butterfly valve. The nominal diameter of the valve is DN < 2500mm, the working pressure is PN < 4.0MPa, and the working temperature is 100 ~ 150 C. In addition, the nominal diameter of the fast closing butterfly valve used in the duct system: DN400 ~ 1200mm is also listed as the development direction. In addition, safety valves meeting earthquake requirements are also urgently needed to develop nuclear power electric valves.
III: Valves for Offshore Oil
The oil production, blowout prevention, water injection, gas injection, underwater equipment and other systems of offshore oil production platforms need to develop some special electric valves which are resistant to sea water and salt spray erosion. These electric valves require strong corrosion resistance, storm resistance and other abnormal external forces, and require reliable sealing, flexible operation and convenient maintenance.
IV: Petrochemical and Electric Valves
The key point of structural adjustment of petrochemical and electric valve products is to develop door-lacking products. As follows:
_High temperature and high pressure regulating valve is used for high temperature and high pressure regulating valve of large thermal power unit. Its structure design should be determined according to its flow characteristics and operation control requirements. It can be single seat, double seat or sleeve structure. The nominal diameter of the control valve is DN50-500mm, nominal pressure is less than 42.0MPa, and operating temperature is 510-570 C.
(2) High temperature, high pressure and large caliber safety valves are used for high temperature, high pressure and large caliber safety valves in steam systems. The design structure can adopt spring type. The key problems to be solved in the design are: setting pressure, return pressure, sealing performance, repetitive action stability and spring fatigue. Its nominal diameter: DN200-400mm; nominal pressure: <5.0MPa; maximum operating temperature: 570 C
IV: Valves for Environmental Protection
The electric valves needed to be developed in this environmental protection system include ceramic seal rotary valves, PVC plastic valves, large sealing surface flat gate valves, stainless steel cock valves, etc.
V: Valves for metallurgical system valves for metallurgical system, because the medium is usually powder and suspended solid particles, coupled with higher temperature, so the requirements for wear resistance, temperature resistance and corrosion resistance of electric valves are higher.
The specific types and parameters of valve development for metallurgical system are as follows:
_The slab gate valve for ash removal is used in the slag removal system of steelmaking plant. The medium of the ash removal system, ash powder, is not only used.
