Swing Check Process planning Valve Ball Check Valve Applicable occasion Plastic Check Valve Standard

Check valve refers to a circular valve valve and by its own weight and medium pressure to block the backflow of the medium. Belongs to automatic valve class, also known as check valve, check valve, return valve or isolation valve. Usually the valve works automatically, opening it under the fluid pressure flowing in the opposite direction, and the fluid pressure and the valve disc act to stop the valve seat to cut off the flow.

Standard: 1) Product standards General Valve Iron Ropin Check Valve GB / T 13932-92 Steel Ropin Check Valve GB 12236-2008 General Valve Iron Stop Valve and Lift Check Valve GB 12233-2006 Double Check Check Valve JB / T 8937-2010 General Requirements for Steel Valves, GB / T 12224-2005 Inspection and Testing of Valves JB / T 9092-19992)

Engineering standard: Code for Acceptance of Construction Quality of Building Water Supply and Drainage and Heating Engineering GB 50242-2002 Code for Construction Quality Acceptance of Ventilation and Air Conditioning Engineering GB50243-2002

Process planning: (1) Quality control of the main blank All parts of the valve are forging parts, forging in strict accordance with the forging process rules and process card, the starting forging temperature, final forging temperature, deformation degree and deformation speed, strictly controlled, and cooled according to the cooling method specified in the process rules. Chemical composition analysis, mechanical properties test, intercrystal corrosion test and metallographic organization analysis of the finished forged products all meet the corresponding standards after analysis, test and determination. The quality of the forging is guaranteed by ultrasonic inspection and liquid penetration test, with 100% ultrasonic flaw detection and evaluation according to RCC-M requirements, and the liquid penetration test and evaluation of all the forging surfaces.(2) Welding In order to improve the quality of overlay welding, the plasma argon arc welding process is adopted for overwelding on the sealing surface of the valve disc and valve seat. At the same time, in order to ensure the welding quality, the welding process used in the production is re-evaluated. (3) Assembly test High-quality products not only need high-precision parts, but also need how to assemble these high-precision parts into high-performance products. Nuclear Sue valve organized a highly experienced, technical, composed of several technicians and senior technicians of assembly, debugging team, responsible for valve assembly, debugging, test, developed parts cleaning process, assembly process, strictly check in assembly and debugging, excellence, to ensure that the valve assembly, debugging success, and conducted all kinds of performance test, the indicators meet the requirements of the design mission. (4) Process inspection A quality plan has been prepared for the valve to ensure that the valve is quality controlled from raw materials, blank input, machining, welding, heat treatment, nondestructive testing, cleaning, assembly, factory test and various type tests, and is recognized and witnessed by the second Research and Design Institute of nuclear industry.

Applicable occasion: Butterfly double valve valve check valve is suitable for high-rise building water supply pipe network, there are certain chemical corrosive medium pipe network, installation space limited pipe network, but also suitable for sewage pipe network. Lift-type silent check valve is suitable for the pipe network with high quality requirements of water supply and drainage engineering; relatively high pressure requirements of pipe network (PN2.5Mpa); can be installed at the outlet of the pump, it is an economical and practical waterproof hammer check valve. Lift type muffler check valve is suitable for water supply and drainage system, high-rise building pipe network, can be installed at the outlet of the pump, the structure is slightly changed, can be used as a suction valve, but not suitable for sewage pipe network. Horizontal check valves are suitable for diving, drainage, sewage pumps, especially for sewage and sludge systems. Turning rubber check valve is suitable for domestic water network; but not for sediment sewage The single valve check valve is suitable for water supply system, petroleum, chemical, metallurgy and other industrial departments is most suitable for places with installation space restrictions.

Fault treatment: 1. The valve flap broken, causing the valve flap break is: the check valve before and after the medium pressure is close to balance and each other "saw" state, the valve flap often and the valve seat flap, some brittle materials (such as cast iron, brass, etc., made of the valve) flap is broken. The prevention method is to use the valve flap check valve as toughness material.2. The causes of medium backflow are: ① sealing surface damage; ② sandwiched into impurities. Repair the sealing surface and clean the impurities to prevent backflow.

Industry development: China's valve industry chain is numerous, but not the valve power. On the whole, China has entered the ranks of the world's valve power, but from the perspective of product quality, China is still a long gap from the valve power. The phenomenon of low production concentration, low valve research and development capacity of high-end products, and low manufacturing technology level of the valve industry still exists, and the import and export trade deficit is constantly expanding. The next few years will be the high-speed shock period of the valve industry, the direct consequence of this high-speed shock is to lead to the expansion of the polarization in the valve cabinet brand camp trend. It is expected that the real valve enterprises that can survive in the market in the next few years are absolutely not so many. But this high-speed shock in the valve industry will bring huge opportunities, and the result of the shock will make the market operate more rational. The road of localization of high-end valves is abnormal "bumpy". Basic parts have become a short board restricting the development of China's manufacturing industry to the high-end. During the 12th Five-Year Plan period, the government will continue to increase the localization of high-end equipment parts and components. Here, we select several representative valves in the key development industries mentioned in the Implementation Plan for the feasibility analysis of import substitution. From the analysis, we can see that the feasibility of valve import substitution in different sub-industries is very different, and the high-end valves are in urgent need of more policy guidance and scientific research support. Valve industry in the national economic development, as an important link in the preparation of the manufacturing industry, plays a very important role. Because there is still a certain gap between China's domestic valve manufacturing level and the international advanced level, Many high parameters, high temperature and high pressure, high pound grade key valves have been dependent on imports, In order to promote the localization of valves, After the "Several Opinions on Accelerating the Revitalization of the Equipment Manufacturing Industry" issued by the State Council, The relevant state departments shall, in accordance with the requirements for the localization of major equipment made by the State, A series of major arrangements have been made, Led by the National Development and Reform Commission, With the China Machinery Industry Federation and the China General Machinery Industry Association, Deployed and formulated the valve localization plan of major equipment in related fields, And repeatedly in coordination with the relevant departments, Now the valve localization in the domestic valve industry has formed a consensus. Actively adopt international standards for product design; absorb foreign excellent design structure; product test and performance test are strictly according to international standards; absorb foreign production process experience for the research and application of new materials; and understand the technical parameters and working conditions of imported high parameter valve products is to speed up the process of localization, promote the continuous update of valve products, and fully realize the localization of valve. With the acceleration of the valve industry restructuring, the future industry will be the valve product quality and safety and product brand competition, products to high technology, high parameters, strong corrosion resistance, high life direction, only through continuous technological innovation, develop new products, technical transformation, to gradually improve the technical level of products, meet the domestic equipment, fully realize the localization of the valve. China's valve manufacturing industry in the huge demand environment, will present a better development prospects.