What is meant by non-standard pressure vessel
 

Non-standard refers to non-standard parts, standard parts only a fixed number of dimensions, such as a gas tank, height, thickness, diameter are clearly defined. But in some engineering practice, often can not be hard set that several sizes, which appeared in the non-standard parts. Non-standard parts are also to meet the safety requirements, and is not a substandard product.

How to design a non-standard pressure vessel

Non-standard pressure vessel design means that the maximum pressure at the top of the set vessel together with the corresponding design temperature is used as the loading condition, and its value is not lower than the working pressure.

General principles of design pressure:

1. The design pressure of the vessel and the meaning of the maximum working pressure of the vessel is not equivalent, but the design pressure is generally taken to be slightly higher than or equal to the maximum working pressure.

2. Pressure vessels equipped with safety relief devices, the design pressure shall not be lower than the opening (setting) pressure of the safety valve and the bursting pressure of the rupture disc device.

3. Containers holding liquefied gases, no insulation device, the design pressure (maximum working pressure) is not less than the saturation vapor pressure of the liquefied gases at 50 ℃; reliable insulation facilities, the design pressure is not less than the saturation vapor pressure at the highest temperature measured in the test.

China non-standard pressure vessel industry market analysis in 2019: products basically realize domestic substitution market concentration to be improved：
 

1、Classification of non-standard pressure vessels

Non-standard pressure vessel mainly refers to industrial production for specific applications, with a specific process function of the irregular, not a series of pressure vessel equipment. According to the different fields of application, the main products of non-standard pressure vessel manufacturing industry can be divided into petrochemical pressure vessel, chemical pressure vessel, coal chemical pressure vessel, nuclear power pressure vessel, non-ferrous metal pressure vessel and other major categories.

Working pressure is one of the most important design parameters of non-standard pressure vessels. From the viewpoint of safety technology, the higher the working pressure of non-standard pressure vessels, the higher the possibility and hazard of rupture and explosion accidents, and the more serious their consequences. In order to carry out hierarchical management and technical supervision of pressure vessels, China currently divides pressure vessels into four categories according to the level of design pressure: low-pressure, medium-pressure, high-pressure and ultra-high-pressure vessels.

2、China's non-standard pressure vessel licensed manufacturers, products basically realize domestic substitution

China's non-standard pressure vessels have experienced a series of processes from scratch, from import-oriented to self-production-oriented, from blind production to standardized production. China has become the largest off-standard pressure vessel market in the Asia-Pacific region due to the growth in demand for electric power in recent years. Future renewable energy and modernization of existing power infrastructure will further promote the market demand for non-standard pressure vessels.

Currently, China's off-standard pressure vessel industry is in a mature stage of development, and the main products have basically realized domestic substitution.

According to ASME statistics, as of 2017, the number of licensed manufacturers in China was 942, of which 31 belonged to the same manufacturer certified in multiple locations, and the actual number of licensed manufacturers was 912.

According to the statistics of ASME Code Products Specialized Committee of CACI (CACI), as of December 31, 2018, China (excluding Hong Kong, Macao and Taiwan) had 939 ASME-certified manufacturers, a net increase of 27 compared with 912 in 2017, an annual growth of 2.9%; the manufacturers held a total of 1,456 certificates, a net increase of 40, a year-on-year growth of 2.8%.

China's licensed manufacturers are mainly concentrated in East China and North and Central South China, of which the three provinces of Jiangsu, Shandong and Zhejiang have the largest number of licensed manufacturers, with the number of licensed manufacturers in the three provinces being 338, 999 and 79 respectively, accounting for 35.9%, 10.5% and 8.4% of the total number of licensed manufacturers in China.

3、China's in-service pressure vessel growth rate slowed down, China's non-standard pressure vessel industry market size scale declined

After nearly a century of development, pressure vessels have been commonly used equipment in human production and life.From 2007 to 2017, the number of pressure vessels in service in China increased year by year, but the growth rate showed a downward trend. By the end of 2017, the number of pressure vessels in service in China was 3.820 million units, with a year-on-year growth of 6.1%.By the end of 2018, the number of pressure vessels in service in China was 3.946 million units, with a year-on-year growth of 3.3%.

From the perspective of metal pressure vessel industry revenue, the market scale of China's non-standard pressure vessel industry declined in 2017 and 2018, and in 2018, the market scale of China's non-standard pressure vessel market was about 71.29 billion yuan, down 10.3% year-on-year.

The decline in the scale of the non-standard pressure vessel industry is mainly affected by two aspects, one is the incremental market decline in the pressure vessel industry; the other is the supply-side reform background, the gradual improvement of the industry standard and the rise of the industry's technical requirements, the backward production capacity to accelerate the elimination of the old and new kinetic energy during the shift of the gears, the industry appeared to be in a phased decline.

4、Low market concentration in China's non-standard pressure vessel industry

From the non-standard pressure vessel listed enterprises non-standard pressure vessel related business revenue situation, in 2018, China First Heavy, National Heavy Duty 5, Tianwo Science and Technology, three pressure vessel related business revenue are more than 1 billion yuan, revenue of 2.517 billion yuan, 1.544 billion yuan and 1.364 billion yuan, respectively, the market share of 3.5%, 2.2% and 1.9%, respectively. The industry has not yet appeared absolute monopoly leading enterprises, market concentration is low.
 

5、Petrochemical industry is the main downstream application market of non-standard pressure vessel

Non-standard pressure vessel is an important equipment in petrochemical, non-ferrous metal smelting, nuclear industry and other industries, among which the demand for non-standard pressure vessel in petrochemical and nuclear power occupies a major share.

In 2018, the demand for non-standard pressure vessels in petrochemical industry accounted for 65.2%, nuclear power industry accounted for 19.9%, non-ferrous metal accounted for 4.3%, and other fields accounted for 10.6%.

In the future, as the industrial Internet and intelligent manufacturing national strategy to promote, non-standard pressure vessels as an important equipment in the traditional industrial sector, its production and operation will gradually approach the direction of automation and intelligence; at the same time, with the promotion of green energy-saving technologies such as "waste heat recovery" and the use of clean fuels, energy saving and emission reduction in the petrochemical and power generation industries will be strengthened. At the same time, with the promotion of "waste heat recovery", the use of clean fuels and other green energy-saving technologies, petrochemical, power generation industry, energy saving and emission reduction efforts to strengthen, non-standard pressure vessels will be energy efficient direction.