GB 17673-1999 Liquefied propylene and propane steel welded gas cylinders
Some standard content:
GB17673—1999
This standard is derived from GB5100—1994 "Welded Steel Cylinders". Both Appendix A and Appendix B of this standard are indicative appendices. This standard is proposed and managed by the National Technical Committee for Standardization of Gas Cylinders. The drafting units of this standard are: Dezhou Chemical Machinery Factory of Shandong Province and Shandong High Pressure Container Factory. The main drafters of this standard are: Shang Xihong, Liu Xiaoru, Shao Shunkui and Zhong Lin. 448
National Standard of the People's Republic of China
Welded steel cylinders for liquefied propylene and propane gases
Welded steel cylinders for liquefied propylene and propane gases1Scope
GB17673—1999
This standard specifies the basic parameters, materials, design, manufacture, test methods, inspection rules and markings, coating, packaging, transportation and storage of welded steel cylinders for liquefied propylene and propane gases (hereinafter referred to as cylinders). This standard applies to cylinders used at normal ambient temperature (-40 to 60°C), with a water pressure test pressure of 3.8 MPa (gauge pressure) and 3.3 MPa (gauge pressure), a nominal volume of 101501, and can be repeatedly filled with liquefied propylene and propane. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. GB/T228—1987 Metal tensile test method GB/T232—1988 Metal bending test method GB/T1804—1992 General tolerances Unspecified tolerances for linear dimensions GB5100--1994 Steel welded gas cylinders
GB/T6397--1986 Metal tensile test specimens GB8335—1998 Special threads for gas cylinders
GB/T9251—1997 Hydrostatic test method for gas cylinders GB/T 12137—1989
Gas cylinder airtightness test method
GB15385—1994 Hydrostatic bursting test method for gas cylinders JB4730—1994 Nondestructive testing of pressure vessels Definitions and symbols
3.1 Definition
Batch: The limited number of steel cylinders produced continuously using the same design, the same grade of material, the same welding process, and the same heat treatment process.
3.2 Symbols
α——gap between the curved surface of the end cap and the sample, mm;b6——misalignment of the weld joint, mm;
c——convex and concave amount of the end cap surface, mm;
d——diameter of the bending axis of the bending test, mm;
D,—inner diameter of the cylinder, mm;
D outer diameter of the cylinder, mm
e maximum and minimum diameter difference of the same cross section of the cylinder body, mm;h—height of the straight edge of the end cap, mm;
Approved by the State Administration of Quality and Technical Supervision on February 11, 1999 and implemented on November 1, 1999
inner convex surface height of the end cap, mm;
shape coefficient of the end cap;
GB 17673—1999
L. Bottle length (including the height of the ends), mm Sample length, mm;
Ratio of the bending axis diameter to the sample thickness;
Nominal working pressure, MPa;
Measured bursting pressure of the cylinder, MPa;
Hydraulic pressure test pressure, MPa;
Inner radius of the corner of the transition zone of the end cap, mm;
Inner radius of the spherical part of the end cap, mm;
S--Design wall thickness of the bottle, mm;
Design wall thickness of the simplified body, mm;
Design wall thickness of the end cap, mm;|| tt||Minimum wall thickness of bottle body, mm;
Thickness of specimen, mm;
Weld width of tensile specimen, mm;
Nominal wall thickness of bottle body, mm;
-Nominal volume, L;
Yield point of material specified in standard, MPa;ap---Tensile strength of material specified in standard, MPa;ObaMeasured tensile strength of material, MPa;
AH——Height inside head (H: + h) tolerance, mm;s—Elongation of short specimen, %;
Weld coefficient;
Element△D;-Inner circumference tolerance, mm.
Basic parameters
Nominal volume and inner diameter
Nominal volume V and inner diameter D of steel cylinder. According to the provisions of Table 1. Table 1
Nominal volume V
Inner diameter D
Note: (bzxZ.net
10~～25
200,230
) values should not be used as much as possible.
4.2 Nominal working pressure and water pressure test pressure The nominal working pressure and water pressure test pressure shall be in accordance with the provisions of Table 2. 450
>25～50
>50～100
300,350
>100～150
5 Material
Medium name
Nominal working pressure P
Water pressure test pressure Ph
5.1 General provisions for materials
According to 5.1 of GB5100--1994.
5.2 Chemical composition
According to 5.2 of GB5100-1994.
5.3 Mechanical properties
GB17673-1999
Liquid propylene
The strength ratio (o./a) of the main material of the steel cylinder should not be greater than 0.8.6 Design
6.1 General design provisions
6.1.1 The internal pressure based on which the wall thickness of the steel cylinder body is calculated is the water pressure test pressure. Liquefied renane
6.1.2 The main welds of the steel cylinder body shall not exceed three, that is, no more than one longitudinal weld and no more than two circumferential welds, MPa
6.1.3 The shape of the steel cylinder head shall be circular [see Figure 1a), dish-shaped as shown in Figure 1b or hemispherical, and the straight edge height of the head h≥25mm. s
H ≥ 0. 2 D;
6.2 Calculation of bottle wall thickness
6.2.1 The designed wall thickness S of the bottle is calculated according to formula (1) and rounded up to one decimal place. S_ =
Wherein, the weld coefficient is 0.9.
6.2.2 The designed wall thickness S of the head is calculated according to formula (2) and rounded up to one decimal place. S.=
R,≤ d, , T≥ 0. 1D.
Wherein, the shape coefficient K of the head is K=1 for the elliptical head (H=0.25D,) and can be found in Figure 2 for other heads.
（1）
·（2）
GB 17673—1999
0. 25 H,/ D,
Applicable to ratio H:/D.between 0.20 and 0.25a)
Applicable to ratio H/D between 0.25 and 0.50b)
6.2.3 The design wall thickness S of the cylinder body shall not be less than the thickness calculated by formula (3) and shall not be less than 2mm: S
0. 50 H/D,
.+++.....***+........++++.( 3 )6.2.4 The nominal thickness of the cylinder body and the head shall be equal. When determining the nominal thickness of the cylinder body, the negative deviation of the steel plate thickness and the process thinning amount shall be considered.
6.3 Openings
According to 5.6 of GB5100-1994.
6.4 Welded joints
According to 5.7 of GB 5100-1994.
6.5 Accessories
GB 17673-1999
6.5.1 The structural design and layout of accessories should facilitate operation and weld inspection. The connecting welds between accessories and the bottle body should avoid the longitudinal and circumferential welds of the bottle body. The structural shape of accessories and their connection with the bottle body should prevent liquid accumulation. 6.5.2 The base should ensure the stability of the cylinder when it is upright and have holes for drainage and ventilation. 6.5.3 The cylinder should be equipped with a fixed cap or a shield welded to the bottle body. 6.5.4 The sealing materials used in the cylinder and its accessories shall not react chemically with the medium contained. 6.5.5 The valve seat thread shall comply with the provisions of GB8335. 6.5.6 The cylinder shall be equipped with a safety valve type safety relief device, and the discharge capacity of the safety valve shall be able to ensure the safety of the cylinder. The opening pressure and return seat pressure of the safety valve shall be in accordance with the provisions of Table 3.
Media Name
Opening Pressure
Return Seat Pressure
7 Manufacturing
Liquid Propylene
Liquid Propane
7.1 Welding Procedure Qualification
7.1.1 Before producing steel cylinders, or when changing the cylinder material, welding material, welding process, or welding equipment, the cylinder manufacturing unit shall conduct welding process qualification.
7.1.2 The welding process qualification can be conducted on the welding process qualification test plate (refer to Figure 6 for dimensions) or directly on the cylinder. The welds for process qualification should represent the main welds of the cylinder (longitudinal welds, girth welds). 7.1.3 The welding process qualification test plate (or cylinder) shall be subjected to visual inspection and 100% radiographic inspection, and the inspection results shall comply with the provisions of 7.3 and 7.4.
7.1.4 The welded joints shall be subjected to tensile and bending tests, and the test sampling locations shall refer to Figure 4, Figure 5 or Figure 6. 7.1.5 The welding process qualification test results shall comply with the provisions of 7.13.4. 7.1.6 The welding process qualification document shall be approved by the chief technical officer of the cylinder manufacturing unit. 7.2 General provisions for welding
According to 5.11 of GB 5100-1994.
7.3 Appearance of weld
According to 5.12 of GB5100-1994.
7.4 Radiographic inspection of welds
7.4.1 Personnel engaged in radiographic inspection of steel cylinders must pass the examination in accordance with the "Qualification Assessment Rules for Boiler and Pressure Vessel Nondestructive Inspection Personnel" issued by the Ministry of Labor and hold a valid certificate. 7.4.2 For steel cylinders with only one girth weld, one out of every 50 (one out of less than 50) shall be selected in the production order for radiographic inspection of the entire length of the weld; for steel cylinders with one longitudinal weld and two girth welds, each longitudinal and girth weld of each steel cylinder shall be subjected to radiographic inspection of no less than 20% of the length of the weld.
7.4.3 The areas to be inspected by radiographic inspection shall include the junctions of longitudinal and circumferential welds. 453
GB17673-1999
7.4.4 The radiographic inspection of welds shall be conducted in accordance with JB4730, with the radiographic quality grade being AB, and the weld defect grade being not less than grade I. 7.4.5 The quality of the butt welds of the cylinder body that have not been inspected by radiographic inspection shall also meet the requirements of 7.4.4. If the defect is found to be only excessive pores after re-inspection, the cylinder manufacturer and the user may negotiate and deal with it. 7.5 Weld repair
According to 5.14 of GB5100-1994.
7.6 Simplified
According to 5.15 of GB5100-1994.
7.7 End cap
7.7.1 The end cap must be made of a whole piece of steel plate. 7.7.2 The shape and size tolerances of the head shall not exceed the provisions of Table 4. Use a sample with a length of 10.3D and 1=0.8D: to check the shape deviation (see Figure 3).
Circumference tolerance
Maximum and minimum diameter difference
Surface concave and convex amount
7.7.3 The measured minimum wall thickness of the head shall not be less than the designed wall thickness of the head. 7.7.4 The depth of longitudinal wrinkles on the straight edge of the head shall not exceed 0.25%D. 7.7.5 Unnoted tolerances of linear dimensions
Unnoted tolerances of linear dimensions shall comply with the following provisions: a) Machined parts are GB/T1804-m;
b) Non-machined parts are GB/T1804-c; c) Length dimensions are GB/T1804-V.
7.8 Assembly
Gap between curved surface and template
7.8.1 All parts of the cylinder shall be inspected and qualified before assembly, and no forceful assembly is allowed. 7.8.2 The misalignment 6 of the butt weld between the head and the cylinder shall not exceed 0.25Sn. 7.8.3 The straightness of the cylindrical body of the cylinder (including the straight edge of the head) shall not exceed two-tenths of its length. 7.8.4 The assembly of accessories shall comply with the provisions of the drawings. 7.9 Surface quality
Inner height tolerance
The outer surface of the cylinder shall be smooth, without cracks, heavy skin, inclusions, pits with a depth exceeding 0.5mm, scratches, corrosion and other defects, otherwise it shall be ground, and the ground part shall be smooth, and its wall thickness shall not be less than the designed wall thickness. 454
7.10 Heat treatment
According to 5.20 of GB 51001994.
7.11 Volume and weight
GB17673-1999
7.11.1 The measured water volume of the cylinder shall not be less than its nominal volume. 7.11.2 After the cylinder is manufactured, the tare weight shall be measured one by one. 7.12 Water pressure test and air tightness test
7.12.1 The water pressure test of the cylinder shall be carried out in accordance with the provisions of GB/T9251, and the test shall be carried out after heat treatment. The water pressure test pressure shall be determined in accordance with 4.2. Maintain the pressure for 3~5min under the water pressure test pressure for inspection. The cylinder shall not have macro deformation or leakage, and the pressure gauge shall not have a drop phenomenon. 7.12.2 The gas-tightness test of the steel cylinder shall be carried out in accordance with the provisions of GB/T12137. The gas-tightness test shall be carried out after the hydraulic pressure test is qualified. The gas-tightness test pressure is the nominal working pressure. The pressure shall be maintained for 1 to 3 minutes under the test pressure, and the tested steel cylinder shall not leak. 7.12.3 If leakage is found on the weld during the hydraulic pressure test and the gas-tightness test, it can be repaired in accordance with the provisions of 7.5. After the repair, the steel cylinder shall be re-heat treated as a whole.
7.12.4 If the weld is repaired in the following situations, it is not necessary to re-heat treat: a) Pinhole leakage;
b) The repair length does not exceed 25mm;
c) The repair of the same weld is not more than two places, and the distance between the two places is not less than 75mm. 7.12.5 The repaired steel cylinder shall be re-tested with hydraulic pressure and gas-tightness according to the requirements of 7.12.1 and 7.12.2. 7.13 Mechanical properties test and water pressure burst test 7.13.1 Sample bottles are taken in batches for mechanical properties test and water pressure burst test. The test bottles must be steel cylinders that have passed the radiographic test and one-by-one inspection.
7.13.2 Mechanical properties samples are cut from the bottle body. For steel cylinders composed of two parts, the test sampling position is as shown in Figure 4; for steel cylinders composed of three parts, the test sampling position is as shown in Figure 5. A-direction
1 tensile specimen
1 transverse face bend specimen
1 tensile specimen
1 transverse back bend specimen
1 tensile specimen
GB17673-1999
1 tensile specimen
1 transverse face bend specimen
1 transverse back bend specimen
1 tensile specimen
1 tensile specimen
1 transverse face bend specimen
1 transverse back bend specimen
1 tensile specimen
7.13.3 The weld section of the specimen shall be in good condition and shall not have defects such as cracks, lack of fusion, incomplete penetration, slag inclusions and pores. 7.13.4 Mechanical test results shall comply with the following provisions: a) The measured tensile strength h and elongation of the cylinder body parent material shall not be less than the lower limit of the parent material standard value. b) The measured tensile strength oba of the welded joint shall not be less than the lower limit of the parent material standard value. c) There is no crack when the welded joint specimen is bent to 100°, and the early cracking of the specimen edge can be ignored. The ratio of the bending axis diameter to the specimen thickness n shall comply with the provisions of Table 5.
Measured tensile strength Oba, MPa
≤430
>430～510
>510～590
>590～685
7.13.5 The hydraulic bursting test of steel cylinders shall be carried out in accordance with GB15385. The test results shall meet the following requirements: a) The measured bursting pressure P shall not be less than the result calculated by formula (4): Ph
b) The volume deformation rate when the steel cylinder ruptures (the increase in the volume of the steel cylinder and the test volume) The ratio of the actual volume of the steel cylinder before the steel cylinder is not less than the provisions of Table 6; Table 6
Tensile strength of cylinder material b, MPa
>360～490
Volume deformation rate, %
c) When the steel cylinder breaks, no fragments are produced, and the bursting hole does not occur on the head (only one girth weld, L≤2D. Except for steel cylinders), longitudinal welds, girth welds (except perpendicular to the girth weld); d) The bursting hole of the steel cylinder is a plastic fracture, that is, there is an obvious shear lip on the fracture, but there is no obvious metal defect. 8 Test method
8.1 Material verification test
According to 6.1 of GB5100--1994.
8.2 Mechanical properties test of welding process qualification test plate GB17673—1999
8.2.1 After the test plate (or steel cylinder) is inspected and qualified according to the requirements of 7.1.3 (sampling is allowed to avoid defective parts), cut the sample from the process qualification test plate according to the requirements of Figure 6, or cut the welded joint test sample from the steel cylinder according to Figures 4 and 5. 50
CC (CCCC (C
400~600
1-Tensile test; 2
Bending test; 3-Discard part
8.2.2 The number of specimens is as follows: 2 tensile specimens, 4 transverse bending specimens (2 for face bending and 2 for back bending). 8.2.3 The weld reinforcement of the specimen shall be removed by mechanical processing to make it flush with the parent material. For uneven specimens, cold leveling can be performed before removing the weld reinforcement
8.2.4 The tensile specimen shall be prepared according to Figure 7, and the tensile test shall be carried out according to GB/T228. R25
250 or as required
8.2.5 The bending specimen shall be prepared according to Figure 8, and the bending test shall be carried out according to GB/T232. During the test, the axis of the bending axis shall be located at the center of the weld. /25
d + 2. 5Sh +100
8.3 Radiographic inspection of welds
According to 6.3 of GB5100---1994.
8.4 Mechanical properties test of parent material and welded joints 8.4.1 Sampling method
8.4.1.1 For cylinders composed of two parts, take one parent material tensile test specimen axially from the cylindrical shell according to Figure 4. If the cylinder is not long enough, take it from the convex part of the head. Take one tensile test specimen, one transverse face bend test specimen and one back bend test specimen from the girth weld. 1457
GB 17673—1999
8.4.1.2 For cylinders composed of three parts, take one parent material tensile test specimen axially from the shell 180° away from the longitudinal seam according to Figure 5, and take one test specimen from any convex part of the head. Take one tensile test specimen, one transverse face bend test specimen and one back bend test specimen from the longitudinal weld. If the girth weld and the longitudinal weld are welded by different welding processes, the same number of test specimens should also be taken from the girth weld. 8.4.2 The processing of welded joint test specimens shall comply with the provisions of 8.2.3. 8.4.3 The preparation and testing of parent material tensile test specimens shall comply with the provisions of GB/T6397 and GB/T228 respectively. 8.4.4 The preparation and testing of welded joint tensile and bending test specimens shall be carried out in accordance with the provisions of 8.2.4 and 8.2.5. 8.5 Weight and volume determination
According to 6.5 of GB5100-1994.
8.6 Bottle wall thickness measurement
According to 6.6 of GB5100-1994.
8.7 Water pressure test
According to 6.7 of GB 5100-1994.
8.8 Air tightness test
According to 6.8 of GB 5100-1994.
8.9 Burst test
According to 6.9 of GB 5100--1994.
8.10 Appearance inspection
Use visual inspection and tools such as weld inspection ruler to inspect the surface of the cylinder, the appearance of the weld and the accessories of the cylinder. 9 Inspection rules
9.1 Material inspection
9.1.1 The cylinder manufacturing unit shall conduct finished product chemical composition verification analysis according to the furnace number and mechanical property verification test according to the batch number for the materials used to manufacture the cylinder body according to the method specified in 8.1. The deviation of the finished product chemical composition verification analysis results and the smelting chemical composition shall comply with the provisions of the material standard.
9.:1.2 The verification analysis test results shall comply with the provisions of 5.1 and 5.2. 9.2 Unit-by-unit inspection
9.2.1 Unit-by-unit inspection of cylinders shall be carried out according to the items specified in Table 7. 9.2.2 For steel cylinders with one longitudinal weld and two girth welds, each cylinder shall be subjected to radiographic inspection for not less than 20% of the total length of the corresponding longitudinal and girth welds. If defects exceeding the standard are found, the radiographic inspection shall be extended by 20% of the length of the weld at both ends of the defect. If the length at one end is insufficient, it shall be supplemented at the other end. If there are still defects exceeding the standard, the weld shall be subjected to 100% radiographic inspection.
9.3 Batch inspection
9.3.1 Batch and sampling rules
9.3.1.1 For steel cylinders with only one girth weld, one cylinder shall be selected for every 50 cylinders (one cylinder shall also be selected if there are less than 50 cylinders) in the production order for radiographic inspection of the entire length of the weld.
9.3.1.2 Steel cylinders shall be grouped into batches of no more than 500 cylinders, and one cylinder for mechanical properties test and one cylinder for burst test shall be selected from each batch of cylinders. 9.3.2 Inspection Items
The inspection items for batch inspection of steel cylinders shall be in accordance with the provisions of Table 7.
9.3.3 Re-inspection Rules
9.3.3.1 In batch inspection, if there are unqualified items, re-inspection shall be carried out. 9.3.3.2 If there is evidence that the test failure is caused by operating error or malfunction of the test equipment in the batch inspection items, a second test may be carried out on the same steel cylinder (if necessary, another cylinder may be selected from the same batch of steel cylinders). If the second test is qualified, the first test may be ignored. 9.3.3.3 If the radiographic inspection of the full length of the weld of the steel cylinder fails according to 9.3.1.1, another 2458
GB 17673-1999
steel cylinders shall be selected from the 50 in the same production sequence for radiographic inspection of the full length of the weld. If there is still one unqualified, radiographic inspection of the full length of the weld shall be carried out on each cylinder. 9.3.3.4 If the mechanical property test or burst test of the steel cylinder fails, it shall be retested according to the provisions of Table 8. The retested steel cylinders can be selected from the same batch.
9.3.3.5 If more than one steel cylinder fails the retest according to 9.3.3.4, the steel cylinders in this batch shall be deemed unqualified. However, it is allowed to repair the steel cylinders in this batch, remove the defects, reheat treat and retest them as a new batch according to the provisions of 9.3. Table 7
Inspection rules
Maximum and minimum diameter difference e
Misalignment of the longitudinal weld b
Height of the longitudinal weld corners E
Straightness
Inner circumference tolerance D,
Surface concave and convex
Maximum and minimum diameter difference e
Gap between curved surface and sample
Inner height tolerance AHi
Longitudinal wrinkles of the straight edge Depth of fold
Misalignment of bad weld joint b
Surface of cylinder
Appearance of weld
Thickness of cylinder wall
Radiographic illumination
Mechanical properties
Hydraulic pressure test
Air tightness test
Burst test
>250500
Note: M--mechanical properties test;
B.Burst test.
Inspection of each piece
Unqualified items
Batch inspection
Inspection method
Judgment basis
7.7.3, 7.9
7.4.2, 7.7.4
Re-inspection items10 Appearance inspection
Use visual inspection and tools such as weld inspection ruler to inspect the surface of the cylinder, the appearance of the weld and the accessories of the cylinder. 9 Inspection rules
9.1 Material inspection
9.1.1 The cylinder manufacturing unit shall conduct finished product chemical composition verification analysis according to the furnace number and mechanical property verification test according to the batch number for the materials used to manufacture the cylinder body in accordance with the method specified in 8.1. The deviation of the finished product chemical composition verification analysis results and the smelting chemical composition shall comply with the provisions of the material standard.
9.:1.2 The verification analysis test results shall comply with the provisions of 5.1 and 5.2. 9.2 Unit-by-unit inspection
9.2.1 Unit-by-unit inspection of the cylinder shall be carried out according to the items specified in Table 7. 9.2.2 For cylinders with one longitudinal weld and two girth welds, each cylinder shall be subjected to a radiographic inspection of not less than 20% of the total length of the corresponding longitudinal and girth welds. If defects exceeding the standard are found, the radiographic inspection shall be extended by 20% of the length of the weld at both ends of the defect. If the length of one end is insufficient, it shall be supplemented at the other end. If there are still defects exceeding the standard, the weld shall be subjected to 100% radiographic inspection.
9.3 Batch inspection
9.3.1 Batch and sampling rules
9.3.1.1 For cylinders with only one girth weld, one cylinder shall be selected for every 50 cylinders (one cylinder shall also be selected if there are less than 50 cylinders) in the production sequence for radiographic inspection of the entire length of the weld.
9.3.1.2 Cylinders shall be grouped into batches of no more than 500 cylinders, and one cylinder each for mechanical properties test and burst test shall be selected from each batch of cylinders. 9.3.2 Inspection items
Batch inspection items for cylinders shall be as specified in Table 7.
9.3.3 Re-test rules
9.3.3.1 In batch inspection, if there are unqualified items, re-testing shall be carried out. 9.3.3.2 If there is evidence that the test failure is caused by operating error or malfunction of the test equipment in the batch inspection items, a second test can be carried out on the same cylinder (if necessary, another cylinder can be selected from the same batch of cylinders). If the second test is qualified, the first test can be ignored. 9.3.3.3 If the radiographic inspection of the full length of the weld of the cylinder fails according to 9.3.1.1, 2458 cylinders should be selected from the 50 cylinders in the same production sequence for radiographic inspection of the full length of the weld. If there is still one unqualified cylinder, radiographic inspection of the full length of the weld should be carried out on each cylinder. 9.3.3.4 If the mechanical property test or burst test of the steel cylinder fails, it shall be retested according to the provisions of Table 8. The retested steel cylinders can be selected from the same batch.
9.3.3.5 If more than one steel cylinder fails the retest according to 9.3.3.4, the steel cylinders in this batch shall be deemed unqualified. However, it is allowed to repair the steel cylinders in this batch, remove the defects, reheat treat and retest them as a new batch according to the provisions of 9.3. Table 7
Inspection rules
Maximum and minimum diameter difference e
Misalignment of the longitudinal weld b
Height of the longitudinal weld corners E
Straightness
Inner circumference tolerance D,
Surface concave and convex
Maximum and minimum diameter difference e
Gap between curved surface and sample
Inner height tolerance AHi
Longitudinal wrinkles of the straight edge Depth of fold
Misalignment of bad weld joint b
Surface of cylinder
Appearance of weld
Thickness of cylinder wall
Radiographic illumination
Mechanical properties
Hydraulic pressure test
Air tightness test
Burst test
>250500
Note: M--mechanical properties test;
B.Burst test.
Inspection of each piece
Unqualified items
Batch inspection
Inspection method
Judgment basis
7.7.3, 7.9
7.4.2, 7.7.4
Re-inspection items10 Appearance inspection
Use visual inspection and tools such as weld inspection ruler to inspect the surface of the cylinder, the appearance of the weld and the accessories of the cylinder. 9 Inspection rules
9.1 Material inspection
9.1.1 The cylinder manufacturing unit shall conduct finished product chemical composition verification analysis according to the furnace number and mechanical property verification test according to the batch number for the materials used to manufacture the cylinder body in accordance with the method specified in 8.1. The deviation of the finished product chemical composition verification analysis results and the smelting chemical composition shall comply with the provisions of the material standard.
9.:1.2 The verification analysis test results shall comply with the provisions of 5.1 and 5.2. 9.2 Unit-by-unit inspection
9.2.1 Unit-by-unit inspection of the cylinder shall be carried out according to the items specified in Table 7. 9.2.2 For cylinders with one longitudinal weld and two girth welds, each cylinder shall be subjected to a radiographic inspection of not less than 20% of the total length of the corresponding longitudinal and girth welds. If defects exceeding the standard are found, the radiographic inspection shall be extended by 20% of the length of the weld at both ends of the defect. If the length of one end is insufficient, it shall be supplemented at the other end. If there are still defects exceeding the standard, the weld shall be subjected to 100% radiographic inspection.
9.3 Batch inspection
9.3.1 Batch and sampling rules
9.3.1.1 For cylinders with only one girth weld, one cylinder shall be selected for every 50 cylinders (one cylinder shall also be selected if there are less than 50 cylinders) in the production sequence for radiographic inspection of the entire length of the weld.
9.3.1.2 Cylinders shall be grouped into batches of no more than 500 cylinders, and one cylinder each for mechanical properties test and burst test shall be selected from each batch of cylinders. 9.3.2 Inspection items
Batch inspection items for cylinders shall be as specified in Table 7.
9.3.3 Re-test rules
9.3.3.1 In batch inspection, if there are unqualified items, re-testing shall be carried out. 9.3.3.2 If there is evidence that the test failure is caused by operating error or malfunction of the test equipment in the batch inspection items, a second test can be carried out on the same cylinder (if necessary, another cylinder can be selected from the same batch of cylinders). If the second test is qualified, the first test can be ignored. 9.3.3.3 If the radiographic inspection of the full length of the weld of the cylinder fails according to 9.3.1.1, 2458 cylinders should be selected from the 50 cylinders in the same production sequence for radiographic inspection of the full length of the weld. If there is still one unqualified cylinder, radiographic inspection of the full length of the weld should be carried out on each cylinder. 9.3.3.4 If the mechanical property test or burst test of the steel cylinder fails, it shall be retested according to the provisions of Table 8. The retested steel cylinders can be selected from the same batch.
9.3.3.5 If more than one steel cylinder fails the retest according to 9.3.3.4, the steel cylinders in this batch shall be deemed unqualified. However, it is allowed to repair the steel cylinders in this batch, remove the defects, reheat treat and retest them as a new batch according to the provisions of 9.3. Table 7
Inspection rules
Maximum and minimum diameter difference e
Misalignment of the longitudinal weld b
Height of the longitudinal weld corners E
Straightness
Inner circumference tolerance D,
Surface concave and convex
Maximum and minimum diameter difference e
Gap between curved surface and sample
Inner height tolerance AHi
Longitudinal wrinkles of the straight edge Depth of fold
Misalignment of bad weld joint b
Surface of cylinder
Appearance of weld
Thickness of cylinder wall
Radiographic illumination
Mechanical properties
Hydraulic pressure test
Air tightness test
Burst test
>250500
Note: M--mechanical properties test;
B.Burst test.
Inspection of each piece
Unqualified items
Batch inspection
Inspection method
Judgment basis
7.7.3, 7.9
7.4.2, 7.7.4
Re-inspection items
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.