China's chemical process pump several main product categories: 1. Roots pump At present, China's domestic roots pump according to the current standard pass rate of about 70%, if compared with the international advanced level, the overall performance gap greater. Mainly manifested in: serious serious shaft seal, domestic shaft seal can not withstand long-term operation, oil leakage is more common; vibration, noise. Some products are poorly balanced, and some gears and bearings are not accurate enough. According to the industry standard, the zero-flow compression ratio and the maximum allowable pressure drop of some products can not meet the standard requirements. Some enterprises are outdated in production technology and equipment and can not guarantee that parts The machining accuracy and assembly accuracy. Due to the above problems, the performance of the Roots pump is not reliable and the failure rate is high. Some pumps will be repaired a few months of operation, with the German company LH Roots pump operation for several years without a huge contrast to repair. Rotary vane pump At present, the overall quality level of rotary vane pump products can meet the requirements of current industry standards. The belt pump (normal speed pump) is about 80% and the direct pump (high speed pump) is about 50%. The main problems that can not meet the requirements of the industry standard are as follows: First, the pumping speed at 2 Pa is too low, which causes the pumping efficiency to fall short of the standard requirements. According to the standard, the suction pump efficiency should be over 45% when the inlet pressure is 2Pa, which ensures the pumping capacity of the pump. 80% of the failed products in the rotary vane pump are due to the low indicator. This is due in part to the lack of compliance with the entry diameter of some of the products, leading to shortcomings; in part, due to component manufacturing and assembly problems, pump backflow, leakage and increased tube resistance increase. Some enterprises due to the lack of detection conditions of the suction efficiency index, the product factory is not properly detected and monitored, so that the index has not been long-term improvement and solution. Second, fuel injection and oil spills. In recent years, the major domestic manufacturers of rotary vane pump fuel injection, oil spills under the great efforts to be resolved, with remarkable results. Such as the installation of oil mist separation device, oil device, improve the transmission shaft machining accuracy, replacement of the inlet shaft seal, etc., but still about 20% of the rotary vane pump fuel injection, oil spills. Third, the pump noise does not meet the standard requirements. However, some new manufacturing enterprises did not solve the noise problem of the pump well. Currently, 20% of the products with unqualified rotary vane pumps are unqualified in noise. In spite of the above problems, on the whole, the production of rotary vane pumps in our country has matured from the design level to the processing and manufacturing to the performance and quality. The quality of the products produced by the major enterprises is relatively stable, and the appearance quality has been significantly improved. In the past long-existing problems of fuel injection and oil spill have been controlled in recent years, the performance of the rotary plate material has been improved, and the reliability of the rotary vane pump has been increased to a certain extent. 2XZ-8A direct-coupled rotary vane pump produced by SDIC Nan Guang Co., Ltd. is one of the few new products in rotary vane pump products in recent years. It has some breakthroughs in terms of technical level from the general-speed pump to high-speed pump, High temperature and high speed operation conditions, parts easy to aging, easy to wear problems. 3. Vacuum Pump At present, China's full range of vacuum pump equipment, quality levels improved steadily, basically to meet the needs of the domestic market. After China's accession to the WTO, the competition in the international market is getting fiercer and fiercer. However, there is still a big gap between the quality standards of vacuum pump equipment in our country. We urgently need to think calmly and study countermeasures so as to catch up with the advanced international standards in the shortest possible time. 4. Slide valve pump Domestic slide valve pump compared with foreign products there is still a big gap. Mainly as follows: noise, vibration. Such as H-150 spool valve pump, most of the domestic products to use anchor bolts, or because of vibration, pump crawling serious; fuel injection, oil spills. Serious pump failure, oil leakage after running, most of the products have this problem; stop the pump back to oil serious, resulting in difficult to start, so that the motor overload; poor stability, reliability, due to backward production and processing equipment, not only low production efficiency, and Poor interchangeability of parts, affecting the stability and reliability of the product. 5. High pressure pump High pressure pump to high pressure ammonia pump and high pressure ammonia pump, for example. High-pressure methylamine pump and high-pressure liquid ammonia pump is urea plant suffered strong corrosion, the most technically difficult pump. Reciprocating plunger structure is often used in medium and small urea plants. Multistage centrifugal and high-speed partial flow are often used in large urea plants. In recent years, reciprocating structure pumps have also emerged. Reciprocating pump unit volume, complex structure, repair inconvenient, prone to fatigue cracking of the pump body, but more reliable operation, higher efficiency. High-speed part of the flow pump with two radial impeller, speed up to 14,000 more rev / min, compact structure, operation is relatively stable, but the sealing and wear problems more prominent, not easy to solve. Multistage centrifugal pump is between the two, its manufacturing is relatively low difficulty, the sealing structure is better, and more reliable. The three types of high-pressure methylamine pump have been developed domestically, in the manufacture and use of less serious problems, but the current product is still mainly rely on imports. 6. Slurry pump Slurry pump to phosphate slurry pump, for example. Phosphoric acid slurry pump is a generic term for all kinds of pumps in the production process of phosphate fertilizer and is a very representative type of pump resistant to strong corrosion and abrasion. In the early stage of development of phosphate fertilizer industry, commonly used chemical corrosion-resistant pump, and some life expectancy is only one week, so the pump industry experts at home and abroad in the phosphate slurry pump structure design, material testing, sealing research conducted a lot of research and development. In the phosphor slurry pump design, the first thing to be solved is corrosion or corrosion and erosion problems. Therefore, special consideration should be given to the structural design and the matching between the pump housing and impeller. Foreign phosphoric acid slurry pump used in metal materials, is based on the media using different series. Domestic manufacturers and research institutes also conducted research on the corrosion performance and wear resistance of various materials to create their own ferritic stainless steel, dual-phase steel, austenitic stainless steel and other materials. Many domestic phosphate slurry pump professional manufacturer, but also the Chinese Academy of Sciences, universities, design institutes, research institutes involved in scientific research and development, phosphoric acid slurry pump localization problem has been basically solved.