The comparison of pressure vessel standard with ASME.doc

1、The comparison of pressure vessel standard with ASMEThe comparison of pressure vessel standard with ASMEThe ASME boiler and pressure vessel code is made by the American society of mechanical engineers (ASME) boiler and pressure vessel committee (BPVC), is one of the earliest application standard in

2、the world, has now been recognized as the worlds most complete technical content, the most widely used pressure vessel standard.In our country in 1982 promulgated the boiler pressure vessel safety supervision provisional regulations and the detailed rules for the implementation, has been clear about

3、 the department of labor as the government departments, responsible for legislation and management. Officially released in 1985 steel pressure vessel design rules marked the beginning of our country to form a unified standard of pressure vessel, was published in 1989, the GB 150-89 steel pressure ve

4、ssel marked the our country has begun to form a mandatory standard GB 150-89 as the core of the pressure vessel standard system framework, after ten years of development, our countrys pressure vessel standards system in most areas have the corresponding standard with foreign standards, technical con

5、tent in the overall level also has reached the international advanced standard.In order to make our pressure vessel products can smoothly enter the international market, in 1984 in lanzhou petroleum and chemical machinery works after having obtained the ASME certification, the first national more po

6、werful pressure vessel manufacturers achieve ASME certification, now has nearly hundred enterprises by ASME certification. But in general, only a handful of companies in China have actually made ASME steel printing products, and most enterprises are only in the certification stage. Hangyang company

7、since 1992 has built more than 40 sets of ASME steel products, export and has installed in the United States, Canada and other developed countries, but also created a lot of in accordance with the ASME design, fabrication, inspection of pressure vessels products (not dozen ASME steel seal). Oxygen i

8、n hangzhou began to design and manufacture of ASME products, the vast majority of people (including design, fabrication, inspection and marketing staff) to not familiar with ASME specification, creating a kind of fear, to a certain extent, affected the ASME products market further develops. After ne

9、arly ten years of design and manufacturing of ASME products, the relevant personnel gradually understand, understand and master the ASME specification. According to the practice experience of hango, the standard of pressure vessel in China is compared and analyzed by the ASME specification for refer

10、ence.The corresponding relationship of the main pressure vessel standardClassification of pressure vessel standards in China are relatively thin, is basically according to the type of pressure vessel and container main materials to formulate the corresponding standards, such as steel, aluminum alloy

11、 pressure vessels, pressure vessels horizontal containers, tower, spherical tank, etc. And ASME specification is not according to the container type, respectively formulate the corresponding standards, only the reference in the design of different load specification, such as the selection of design

12、pressure is less than 20 mpa ASME code, the first first volume, the selection of design pressure is less than 70 mpa ASME code, the first second volume, the selection of design pressure is greater than 70 mpa archies of ASME code, the first third. The corresponding relationship between the main pres

13、sure vessel standardsStandard system, revisionChinas national standards of pressure vessel pressure vessel is by the national standardization technical committee shall be responsible for the preparation, revision, after approved by the state bureau of quality and technical supervision issued. The re

14、levant industry standards are compiled and revised by the standardization committees of various industries,Approved and issued by various departments of the state economic and trade commission. Around the standards, the safety supervision department according to the state bureau of quality and techn

15、ical supervision issued by the pressure vessel safety technology and supervision code and the provisions of the relevant standards to control and supervision of the pressure vessel design, manufacture and test each link, ensure product quality and safety use. Each committee for standardization accor

16、ding to understand, collection of standard use opinion and the suggestion, is responsible for the organizations set of standard revision work, and the original examination and approval department for examination and approval after award, implementation.ASME boiler and pressure vessel committee (BPVC

17、) held a meeting on a regular basis, study the ASME standard revision work, approved by the BPVC specification revision Suggestions will be submitted to the national standards institute (ANSl), and published in the American journal of Mechanical Engineering, with open spoke with all those concerned

18、about this problem, the revision Suggestions of the provisions in the public consultation period and the ASME after final approval, the publication of the ASME specification in December 31 each year shall be published in the supplement. Specification after the amendments approved by ASME, starts the

19、 supplement publication date shown in use, in addition to the first the material in the volume of A and B two revision of the standard, the following year on July 1, become mandatory requirements, except where the contract signed before this. The revision of the material standards is carried out by

20、the American institute of materials testing (ASTM) and other accredited national institutions or international institutions, which ASME often adopts. But it is important to note that the pressure vessel manufacturer who use relaxed compared to the original request on revised terms, the installation

21、must be convinced that pressure vessel for they have been approved to be under the jurisdiction of authority, or may not be used.Design ideas and safety coefficientsThe basic design of the pressure vessel is a membrane stress or maximum direct stress must not exceed the allowable stress. The theory

22、of calculating the basis of stress is the maximum stress theory. National pressure vessel standards are applied in the design ideas, standard published in the allowable stress of the safety factor, it is lower than the measurement of performance value given: (1) the complexity of the stress evaluati

23、on method; (2) a degree of stress concentration and its type; (3) a degree of inhomogeneity of the material; (4) the geometry factor; (5) defects in weld joints. Specified in the national standard of safety coefficient is different, the main is based on experience, experimental evidence and theoreti

24、cal assessment, at the same time with the prescribed standards for materials, calculation methods, manufacturing and inspection requirements.4 weld joint coefficientsCoefficient of welded joint in ASME specification only depends on the type and degree of nondestructive testing for welding joints, an

25、d has nothing to do with any other joint degree of nondestructive testing, namely A container of different joint can use different coefficient of welded joint, the A, B, C, D four types of welded joint are rules on the coefficient of welded joint, while allowing the reduced coefficient of welding jo

26、int and exempt from nondestructive testing requirements.In GB 150 in our country, especially A and class B coefficient of welded joint of welded joint, are not allowed to use reduced coefficient of welding joint and exempt from nondestructive testing requirements, product manufacturing must be after

27、 the completion of A and B type connector for rays or ultrasonic testing. The welding joints for steel and aluminum are compared for the steel and aluminum, and see table 3.Table 3 welding joints coefficients are compared5 strength calculationIn the design of the pressure vessel,Make clear a regulat

28、ion in our country let rules pressure vessel, longitudinal welds shall be made for the welding test plate test for the necessary drawing, cold bending and impact test, all belong to one of the following situations of each pressure vessel shall be made for product welding test plate:(1) mobile pressu

29、re vessel (except for mass production);(2) pressure vessels designed to be more than 10MPa;(3) spherical tank welded in situ;(4) a pressure vessel made from a medium or high pressure vessel made of non-ferrous metal, or a high-strength steel produced by the use of sigma b greater than 540MPa;(5) pre

30、ssure vessels welded by different types of steel (different groups);(6) design drawings or the pressure vessel of the users request to produce the product welding test panel;(7) the pressure vessel for each of the product welding test plates shall be made in GB 150.And ASME specification first volum

31、e the first volume of the qualified welding procedure qualification are not required to do product welding test plate, while the following situation requires making product welding test plate as stipulated in the specification:(1) the coefficient of welding joint is not greater than 0.8, with ASME s

32、pecification given any pressure welding welding method (except for resistance welding) joint, on its container or parts, such welds shall be made for product welding test plate specimen can be taken from the shell itself or from the extension of longitudinal weld parts, containers without longitudin

33、al weld can be taken from the same material and same thickness and by the same process of welded plates, and cut a small section of tensile samples and two lateral sample test.(2) if asked to do welding procedure qualification welding seam and heat affected zone of impact test, vessel impact test pl

34、ate should be used for single or more containers A few furnace steel grade in A furnace for making sheet metal, for class A connector, test plate at the end of may should become the joint product of extended part, try to make the plate welding parts as close as possible to the container welding join

35、t quality and form. For welding process, different class B and class A joint joint test plate should be under the same welding conditions, welding manufacturing container, use the same type of equipment, the same location, the same welding technology, and welding shall be carried out with the weldin

36、g of the product at the same time, or at the start of welding products.10 for nondestructive testingNondestructive testing method for defect detection and positioning, measurement, assessment and evaluation will not undermine its future usefulness and usability, in the process of pressure container

37、manufacturing, mainly used for detecting material, weld and manufacture of parts and components of surface and internal physical structure or shape of any interruption or defects. Our country 150 GB and ASME code, the first first volume of nondestructive testing personnel qualification, weld transil

38、lumination proportion, assessment requirements, there are certain differences in such aspects as shown in table 7.11 welding repairGBl50 regulation in our country must by a certified welder welding repair process according to the evaluation of qualified, weld repair should not be more than twice of the same parts, such as more than two times, before the repair shall be approved by the head pressure vessel manufacturing technology, repair times, location and repair of containers should be debited to certificate of quality. The ASME specifica