In the petrochemical industry, valves are widely used pipeline components that have not yet received enough attention. The recent major accident of Lanzhou Petrochemical reminds us once again to pay attention to valve safety, timely inspection and maintenance to prevent problems before they occur. and the material procurement department should enhance the knowledge of the valve, so as to purchase the safety valve suitable for the petroleum and petrochemical industry.

Need to improve valve quality
According to incomplete statistics, there are about 6,000 valve manufacturers in China, of which more than 900 have an annual output value of more than 5 million yuan. Yongjia County, Zhejiang Province, which is known as the "Hometown of Valves in China", has more than 300 kinds of valves and more than 3,000 specifications. It is widely used in large state-owned enterprises and key engineering equipment. Today, after years of development, the number of valve companies in China ranks first in the world.

From the perspective of product conditions, China''s valve industry has been able to produce more than a dozen categories of products, such as gate valves, globe valves, ball valves, butterfly valves, safety valves, check valves, throttle valves, plug valves, pressure reducing valves, diaphragm valves, The maximum operating temperature of traps, emergency shut-off valves, etc. reaches 570 ° C, the lowest is -196 ° C, the highest pressure is 600MPa, and the largest diameter reaches 5350 mm.

In view of the rapid development of the valve industry, the industry generally believes that the valve has broad development space in China. This is mainly due to the support of national policies and the strong demand of the valve product market. With the gradual promotion of the national policy for the revitalization of the equipment manufacturing industry, the development of general basic manufacturing industry has been further supported. In particular, the start of several centuries-old projects such as "West-to-East Gas Transmission", "West-to-East Power Transmission", and "South-to-North Water Diversion" projects require a large number of valve products. In addition, China is facing the advent of the industrialization era. Large petrochemical industry, electric power industry, metallurgical industry, chemical industry and urban construction, and other large valve users will increase demand for valve products. For example, during the "Eleventh Five-Year Plan" period of the power industry, the total number of valves required for large and medium-sized coal-fired power generation projects is estimated to total 153,000 tons of valves, with an average annual demand of 30,600 tons. The average annual demand is 792 million yuan. In addition, China is gradually becoming the world''s largest processing plant, and the processing and manufacturing of valve products is facing greater development space.

However, there are still some problems in China''s valve industry. For example, China''s valve enterprises are mainly low-level, small-scale, family workshop enterprises. In terms of products, due to repeated investment and insufficient technology introduction, the leading products of China''s valve enterprises are still low-quality popular products. At present, various valves produced by Chinese enterprises generally have the disadvantages of external leakage, internal leakage, low appearance quality, short life, inflexible operation, and unreliable valve electric and pneumatic devices. Some products are only equivalent to the early 1980s. At the international level, some high-temperature, high-pressure and valves required on key devices still rely on imports. In addition, China''s valve industry has a large gap with foreign companies in terms of industrial structure, the valve industry''s industrial chain, and the degree of professionalism of the industry.

Most of China''s valve products are hovering at the low end, and the absence of high-end valves in the complex conditions of nuclear power, petrochemical and other industries has led to China''s valves being far ahead in quantity but losing in quality to foreign countries. According to statistics from relevant departments, the annual turnover of China''s valve market is about 50 billion yuan, of which more than 10 billion yuan is occupied by foreign valve companies. According to industry insiders, in China''s current valve market, in addition to low-pressure valves reaching acceptable levels in the international market, high-pressure valves still need to rely heavily on imports.

Precautions in valve procurement
In view of the important role of valves in production, higher requirements have been placed on valve purchasers. In various chemical, petrochemical, and oil and gas installations, pipeline material costs account for about 15% to 20% of the total project investment, and valves account for 40% to 50% of the pipeline material costs. Therefore, no matter from the use point of view or from an economic point of view, the selection and procurement of valves will inevitably be highly valued by the investment or contractor.

It is understood that chemical valves have four characteristics, namely: multiple types, specifications, and types; complex and harsh working conditions; complex structures, high technical requirements, and difficult manufacturing, so they are called small equipment; they are important but It is also the weakest link in pipeline equipment. These characteristics make design, selection, material selection and manufacturing of valves difficult. Therefore, whether the valve selection (including type, material, form, etc.) is proper, and the quality of the valve manufacturing quality will directly affect the operation of the device and even endanger the life and safety of the plant and operators. According to experts, careful consideration should be given to the general requirements, valve standards, transmission gearboxes, operating mechanisms, internal and external anticorrosion and other factors when purchasing valves.

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