Valves are an important part of large-scale complete sets of equipment, mainly used for cutting, throttling, regulating pressure and changing flow direction of process pipeline media (material, water, steam, air and oil). The quality of the valve directly affects the normal production, safe operation and environmental pollution of these devices and plays a vital role. There are many kinds of valve specifications, such as gate valve, globe valve, check valve, ball valve, safety valve, pressure reducing valve, steam trap, butterfly valve and special purpose valve, etc., which have wide application and large dosage. According to incomplete statistics and rough estimates, the investment in valves in a large-scale complete plant accounts for about 3% to 5% of the total investment in equipment. Let Street Light,Spot Lights Outdoor,Outdoor Garden Lighting,Waterproof Led Light JIANGMEN MICHEN LIGHTING CO.,LTD , https://www.jmledbulb.com
(l) Valve manufacturers and production conditions There are about 180 valve enterprises managed at the county level or above, including 19 key enterprises, and there are more than 2,000 townships and individual enterprises of a certain scale. It is difficult for small individual manufacturers to count, township enterprises and individuals. The manufacturers are mostly distributed in Jiangsu, Zhejiang and Central Plains. In the valve industry, state-owned large and medium-sized enterprises, especially backbone enterprises, still have great advantages in valve manufacturing and technical strength. Some of these manufacturers use resin sand line modeling. The main components of the valve are processed on CNC machine tools, automatic lines or combination machine tools. The sealing surface is divided into spray welding technology, the valve design uses CAD technology, and three-dimensional solid modeling. Advanced technology has promoted the improvement of valve production level and product quality, and the development of science and technology is unstoppable. However, most of the valve manufacturers cast smelting equipment outdated, mainly by hand styling, machining is mostly general machine tools and single-knife cutting, testing equipment is not perfect or does not meet the standard. In recent years, some small and medium-sized valve manufacturers have strengthened management personnel, laid the foundation, equipment and technology, and gradually improved the production technology level, product quality, product quality, market grasp, considerable economic benefits, and competition with large or key enterprises. The strength and development prospects cannot be underestimated.
(2) Product level Through the implementation of national standards, technology introduction, strengthening testing and testing methods, old product transformation and improving design and process level, China's valve product level has been greatly improved in the past 20 years, and the variety specifications have increased greatly, especially in Hard-sealed butterfly valves, hard-sealed ball valves, and slab gate valves have increased in types and products (14 categories of valves currently have nearly 2,000 series, more than 12,000 specifications). The ordinary valves with a large quantity and a large area have basically reached the level of foreign countries in the 1980s. These valves are similar in terms of product structure and materials to valves produced in foreign countries in recent years, and can be produced according to foreign standards, but only in product quality. It is not stable enough and has a certain gap with developed countries. However, in some special valves (such as automatic control valve, hard seal ball valve, minimum flow valve, ash removal slag valve, main steam isolation valve and stabilizer safety valve, etc.), high-parameter valve (such as the use temperature is higher than 700 ° C, caliber More than lm ball valve), valve material (anti-hydrogen sulfide material, urea steel and carbon fiber composite material) and valve transmission and other aspects of the gap with foreign countries, the shortage of varieties, should be through the introduction of technology (including the valve to the introduction of the device Use design) and technical research to solve it step by step. The matching capacity of domestic valves can basically meet 300,000 t/a ethylene, 300,000 t/a synthetic ammonia, 520,000 t/a urea, 60,000 t/a high pressure polyethylene, 80,000 t/a polypropylene, 60,000 tons. /a ethylene glycol, 80,000 t/a vinyl chloride, 50,000 t/a acrylonitrile, 30,000 t/a acetaldehyde, 45,000 t/a butadiene, 2.5 million t/a refinery, 30,000 m3 /h air separation, 30MW thermal power station, 30MW nuclear power plant and long-distance pipeline and other devices. The scale of large-scale foreign complete sets of equipment has been continuously expanded, and the matching level of valves has been promoted. Domestically, there is such a development trend, but the supporting capacity has a large gap compared with developed countries, mainly reflected in special valves and high Parameter valves, control systems and drive units.