The continuous development of the valve industry (1967-1978)
01 Industry development is affected
From 1967 to 1978, due to the great changes in the social environment, the development of the valve industry has also been greatly affected. The main manifestations are:
1. The valve output is sharply reduced, and the quality is significantly reduced
2. The valve scientific research system that has begun to take shape has been affected
3. Medium pressure valve products become short-term again
4. Unplanned production of high and medium pressure valves began to appear
02 Take measures to lengthen the “valve short line”
The quality of products in the valve industry has declined seriously, and after the formation of short-term high and medium pressure valve products, the state attaches great importance to this. The Heavy and General Bureau of the First Ministry of Machinery established a valve group to be responsible for the technical transformation of the valve industry. After in-depth investigation and research, the valve team put forward the “Report on the Opinions on the Development of Production Measures for High and Medium Pressure Valves”, which was submitted to the State Planning Commission. After research, it was decided to invest 52 million yuan in the valve industry to carry out technical transformation to solve the problem of serious shortage of high and medium pressure valves and quality decline as soon as possible.
1. Two Kaifeng meetings
In May 1972, the First Machinery Department held a national valve industry work symposium in Kaifeng City, Henan Province. A total of 125 units and 198 representatives from 88 valve factories, 8 relevant scientific research and design institutes, 13 provincial and municipal machinery bureaus and some users attended the meeting. The meeting decided to restore the two organizations of the industry and the intelligence network, and elected Kaifeng High Pressure Valve Factory and Tieling Valve Factory as the high-pressure and low-pressure team leaders respectively, and Hefei General Machinery Research Institute and Shenyang Valve Research Institute were responsible for the intelligence network work. The meeting also discussed and studied issues related to “three modernizations”, improving product quality, technical research, product division, and developing industry and intelligence activities. Since then, industry and intelligence activities that have been interrupted for six years have resumed. These measures have played a great role in promoting valve production and reversing the short-term situation.
2. Resume industry organization activities and information exchange
After the Kaifeng Conference in 1972, industry groups resumed their activities. At that time, only 72 factories participated in the industry organization, and many valve factories had not yet participated in the industry organization. In order to organize as many valve factories as possible, each region organizes industry activities respectively. Shenyang High and Medium Pressure Valve Factory, Beijing Valve Factory, Shanghai Valve Factory, Wuhan Valve Factory, Tianjin Valve Factory, Gansu High and Medium Pressure Valve Factory, and Zigong High Pressure Valve Factory are respectively responsible for the Northeast, North China, East China, Central South, Northwest, and Southwest Regions. During this period, the valve industry and intelligence activities were diverse and fruitful, and were very popular with factories in the industry. Due to the development of industry activities, frequent exchanges of experience, mutual help and mutual learning, it not only promotes the improvement of product quality, but also enhances the unity and friendship between various factories, so that the valve industry has formed a unified whole, in unison, hand in hand Going forward, showing a vibrant and growing scene.
3. Carry out the “three modernizations” of valve products
In accordance with the spirit of the two Kaifeng meetings and the opinions of the Heavy and General Bureau of the First Ministry of Machinery, the General Machinery Research Institute once again organized a large-scale valve “three modernization” work with the active support of various factories in the industry. The “three modernizations” work is an important basic technical work, which is an effective measure to accelerate the technological transformation of enterprises and improve the level of valve products. The valve “three modernizations” working group works according to the “four good” (easy to use, easy to build, easy to repair and good matching) and “four unification” (model, performance parameters, connection and overall dimensions, standard parts) principles. The main content of work has three aspects, one is to simplify the merged varieties; the other is to formulate and revise a batch of technical standards; the third is to select and finalize products.
4. Technical research has promoted the development of scientific research
(1) Development of scientific research teams and construction of test bases At the end of 1969, the General Machinery Research Institute was relocated from Beijing to Hefei, and the original flow resistance test device was demolished, which greatly affected scientific research. In 1971, scientific researchers returned to the team one after another, and the valve research laboratory increased to more than 30 people, and was commissioned by the ministry to organize technical research. A simple laboratory was built, a flow resistance test device was installed, and a specific pressure, packing and other test machines were designed and manufactured, and the technical research on valve sealing surface and packing began.
(2) Main achievements The Kaifeng Conference held in 1973 formulated the technical research plan for the valve industry from 1973 to 1975, and proposed 39 key research projects. Among them, there are 8 items of thermal processing, 16 items of sealing surface, 6 items of packing, 1 item of electric device, and 6 items of test and performance test. Later, in the Harbin Welding Research Institute, Wuhan Material Protection Research Institute, and Hefei General Machinery Research Institute, special personnel were appointed to organize and coordinate regular inspections, and two work conferences on the basic parts of high and medium pressure valves were held to sum up experience, mutual assistance and exchange, and formulated 1976 -Basic parts research plan in 1980. Through the unanimous efforts of the whole industry, great achievements have been made in technical research work, which has promoted the development of scientific research in the valve industry. Its main results are as follows:
1) Tack on the sealing surface. The sealing surface research aims to solve the problem of internal leakage of the valve. At that time, the sealing surface materials were mainly 20Cr13 and 12Cr18Ni9, which had low hardness, poor wear resistance, serious internal leakage problems in valve products, and short service life. Shenyang Valve Research Institute, Harbin Welding Research Institute and Harbin Boiler Factory formed a triple-combination research team. After 2 years of hard work, a new type of chrome-manganese sealing surface surfacing material (20Cr12Mo8) was developed. The material has good process performance. Good scratch resistance, long service life, and no nickel and less chromium, resources can be based on domestic, after technical appraisal, it is very valuable for promotion.
2) Filling research. The purpose of the packing research is to solve the problem of valve leakage. At that time, the valve packing was mainly oil-impregnated asbestos and rubber asbestos, and the sealing performance was poor, which caused serious valve leakage. In 1967, the General Machinery Research Institute organized an external leakage investigation team to investigate some chemical plants, oil refineries and power plants, and then actively carried out anti-corrosion test research on packing and valve stems.
3) Product performance testing and basic theoretical research. While carrying out technical research, the valve industry also vigorously carried out product performance testing and basic theoretical research, and achieved many results.
5. Carry out technological transformation of enterprises
After the Kaifeng Conference in 1973, the whole industry carried out technological transformation. The main problems existing in the valve industry at that time: First, the process was backward, the casting was completely hand-made, single-piece casting, and general-purpose machine tools and general-purpose fixtures were generally used for cold working. It is because the varieties and specifications of each factory are excessively duplicated, and the number is large in the whole country, but after the distribution of each factory, the production batch is very small, which affects the exertion of production capacity. In response to the above problems, the Heavy and General Bureau of the First Ministry of Machinery put forward the following measures: organize the existing high and medium pressure valve factories, make unified planning, rationally divide labor, and expand mass production; adopt advanced technology, establish production lines, and cooperate in key factories and blanks. 4 cast steel blank production lines have been established in the steel casting workshop, and 10 cold processing production lines of parts have been established in six key factories; a total of 52 million yuan has been invested in technological transformation.
(1) Transformation of thermal processing technology In the transformation of thermal processing technology, technologies such as water glass tidal shell mold, fluidized sand, tidal mold and precision casting have been popularized. Precision casting can realize chip-less or even chip-free machining. It is suitable for gate, packing gland and valve body and bonnet of small-diameter valves, with obvious economic benefits. In 1969, Shanghai Lianggong Valve Factory first applied the precision casting process to valve production, for PN16, DN50 gate valve body,
(2) Transformation of cold working technology In the transformation of cold working technology, special machine tools and production lines are used in the valve industry. As early as 1964, Shanghai Valve No. 7 Factory designed and manufactured the gate valve body crawler type semi-automatic production line, which is the first low-pressure valve semi-automatic production line in the valve industry. Subsequently, Shanghai Valve No. 5 Factory designed and manufactured a semi-automatic production line of DN50 ~ DN100 low-pressure globe valve body and bonnet in 1966.
6. Vigorously develop new varieties and improve the level of complete sets
In order to meet the needs of large-scale complete sets of equipment such as petroleum, chemical industry, electric power, metallurgy and petrochemical industry, the valve industry is vigorously developing new products at the same time of technological transformation, which has improved the matching level of valve products.
03 Summary
Looking back on 1967-1978, the development of the valve industry was once greatly affected. Due to the rapid development of petroleum, chemical, electric power, metallurgy and coal industries, high and medium pressure valves have temporarily become “short-term products”. In 1972, the valve industry organization began to resume and carry out activities. After the two Kaifeng conferences, vigorously carried out “three modernizations” and technical research work, setting off a wave of technological transformation in the entire industry. In 1975, the valve industry began to rectify, and the industry production took a turn for the better.
In 1973, the State Planning Commission approved the infrastructure measures for increasing production of high and medium pressure valves. After the investment, the valve industry has carried out potential transformation. Through technological transformation and promotion, some advanced technologies have been adopted, so that the level of cold processing in the whole industry has been improved to a certain extent, and the degree of mechanization of thermal processing has been improved to a certain extent. After the promotion of the plasma spray welding process, the product quality of high and medium pressure valves has been improved a lot, and the problem of “one short and two leakage” has also been improved. With the completion and functioning of 32 infrastructure measures projects, China’s valve industry has a stronger foundation and greater production potential. Since 1970, the output of high and medium pressure valves has continued to grow. From 1972 to 1975, the output increased from 21,284t to 38,500t, with a net increase of 17,216t in 4 years, equivalent to the annual output in 1970. The annual output of low-pressure valves has been stable at the level of 70,000 to 80,000 tons. During this period, the valve industry vigorously developed new products, not only the varieties of general-purpose valves have been greatly developed, but also special valves for power stations, pipelines, ultra-high pressure, low temperature and nuclear industry, aerospace and other special-purpose valves have also developed greatly. If the 1960s was a period of great development of general-purpose valves, then the 1970s was a period of great development of special-purpose valves. The supporting capacity of domestic valves has been greatly improved, which basically meets the development needs of various sectors of the national economy.
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