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Mechanical Industry Standard of the People's Republic of China
JB/T6171-92
Multi-layer Metal Bellows Expansion Joints
Published on May 15, 1992
Implemented on January 1, 1993
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Mechanical Industry Standard of the People's Republic of China
Multi-layer Metal Bellows Expansion Joints
Subject Content and Scope of Application
JB/T6171-92
This standard specifies the classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of multi-layer metal bellows expansion joints.
This standard applies to circular cross-section multi-layer U-shaped metal bellows expansion joints for pipeline thermal compensation. This standard also applies to circular cross-section multi-layer U-shaped metal bellows expansion joints (hereinafter referred to as expansion joints) for pipeline shock absorption and flexible connection. 2
Referenced standards
GB3323 Radiography and quality classification of steel fusion welded butt joints GB/T12777 General technical conditions for metal bellows expansion joints GB150
Steel pressure vessels
GB1183 None
Terms and definitions of shape and position tolerances
GB2828
GB2829
JB2536
Counting sampling procedures and sampling tables for batch inspection (applicable to inspection of continuous batches)Counting sampling procedures and sampling tables for periodic inspection (applicable to inspection of production process stability)Painting, packaging and transportation of pressure vessels
Packaging storage and transportation pictorial signs
GB6388 Shipping and receiving signs for transportation packaging
3 Product classification
3-1 Varieties and codes
3-1-! The varieties and codes of expansion joints are as specified in Table 1. Table 1
Axial type internal pressure type multi-layer metal corrugated expansion jointAxial type external pressure type multi-layer metal corrugated expansion jointAxial type pressure balance type multi-layer all-metal corrugated expansion jointTransverse type unidirectional multi-layer all-metal corrugated expansion jointTransverse type universal multi-layer metal corrugated expansion jointAngle type unidirectional multi-layer metal corrugated expansion jointAngle type universal multi-layer metal corrugated expansion jointStructural type approved by the Ministry of Machinery and Electronics Industry in 1992-05-15
Straight pipe type
Bent pipe type||tt ||Hinged type
Universal ring type
Tie rod type
Hinged type
Universal ring type
Connection mode
Melting tube type
Flange type
1993-01-01Implementation
JB/T6171-92
31-2The typical structural schematic diagrams of expansion joints are shown in Figures 1, 2, 3, 4, 5, 6, 7, 8 and 9. Figure 1 Axial internal pressure type -
Figure 2 Axial external pressure type - ZW
Figure 3 Axial pressure balanced straight pipe type - ZPZ
JB/T6171-92
Figure 4 Axial pressure balanced elbow type ZPW
Figure 5 Transverse one-way type - H
Figure 6 Transverse universal ring type - HW
Figure 7 Transverse universal pull rod type - HL
3.2 Marking
Composition of marking:
JB/T617192
Figure 8 Angular straight type - J
Figure 9 Angular universal ring type - JW | |tt||Standard number
Connection method
-Total compensation
Working temperature
Nominal pressure
-Nominal diameter
Marking example:
Axial internal pressure multi-layer metal bellows expansion joint Z, nominal diameter DN=400mm, nominal pressure P=1·6MPa, working temperature T-300℃, total compensation X200mm, flange connection F, its marking is: Z400-1.6-300/200FJB/T××××-××Technical requirements
41 Materials
Common materials for expansion joints are shown in Table 2.
20~400℃
-20~300℃
JB/T6171-92
Wavelength tube
OCr19NI9OCr18NI11TlOCr17NI12Mo208F,20.A3.16Mn
Note: If there are special requirements, the supply and demand parties shall negotiate to resolve. 42 Appearance
Flange, end pipe
And accessories
4-2.1 The corrugation shape of the bellows in the expansion joint should be uniform, and its surface is allowed to have slight mold indentations, and there should be no obvious unevenness and scratches greater than the negative deviation of the single-layer wall thickness, and there should be no defects such as welding slag and rust spots. 42·2 There should be no slag and splashes on the surface of each part of the expansion joint, and the installation of each accessory should comply with the requirements of the drawings. The carbon steel surface should be painted evenly, and there should be no damage to the flange sealing surface and the end pipe weld.
43 Structure
431 Series parameters
The working temperature of the expansion joint is 20～400℃; the nominal pressure is 0-10, 025, 060, 1-00, 1-60, 250MPa; the nominal diameter and total compensation are shown in Table 3. If there are special requirements, it can be designed separately. 432 Structural dimensions
432.1 The inner diameter, outer diameter, wavelength, outer diameter of the outer sleeve, pipe diameter and deviation of the bellows shall comply with the requirements of the design drawings. 432.2 The circumference of the end pipe and intermediate pipe of the expansion joint and the allowable deviation of the expansion joint length are as specified in Table 4. Table 3
Project name
Axial type
Nominal diameter
Total compensation
Project name
Axial type
Nominal diameter
Total compensation
Project name
Axial type
Nominal diameter
Total compensation
Project name
Axial type
Nominal diameter
Total compensation
JB/T6171-92
Continued Table 3
Project Name
Axial Type
Nominal Diameter
Total Compensation
Project Name
Transverse Type
Nominal Diameter
Total Compensation
Project Name
Transverse Type
Nominal Diameter
Total Compensation
Note: Nominal pressure of expansion joint:
JB/T 6171-92
Continued Table 3
Item Name
Angular Type
Nominal Diameter
①01~06MPa, applicable to nominal diameter of 25~2000mm;②01~16MPa, applicable to nominal diameter of 25~1200mm③01~2.5MPa, applicable to nominal diameter of 25~800mmTotal Compensation
8 (°)
Item Item name
Angular type
Nominal diameter
Total compensation
Nominal diameter DN
Permissible deviation of circumference
Permissible deviation of expansion joint length
433Structural requirements
≤800
JB/T6171-92
>800~1200
There shall be no impurities such as water, oil, and dirt between the layers of the bellows in the expansion joint. 434Welding
4341When the bellows is rolled with steel plates, no girth weld is allowed. >1200~1600
>1600~2000
4342 When the thickness of the longitudinal weld of the corrugated pipe is less than or equal to 0.8mm, the spacing between adjacent welds shall be greater than 150mm; when the thickness of the pipe is greater than 0.8mm, the spacing between adjacent welds shall be greater than 250mm, and the number of welds shall not exceed that specified in Table 5. 4.3.43 There shall be no defects such as cracks, slag inclusions, pores, arc pits, etc. in the welds of each part of the expansion joint, and the size of the weld leg shall meet the requirements of the drawings. If there are special requirements for the load-bearing parts of the expansion joint, the welds shall comply with the Class II regulations in GB3323, and the longitudinal welds of the corrugated pipe shall refer to the relevant regulations in GB3323. Table 5
Broken length
≤1000
≤200
43-5 Connection between expansion joint and pipeline and equipment. >200~600
>600~1200
435-1 When the connection is butt welding, the pipe ends at both ends shall be grooved at 30±25°. 43-5-2 When the connection is flange connection, it shall be in accordance with the relevant flange standards. 44 Shape and position tolerance
44·1 The roundness tolerance of the pipe ends at both ends of the expansion joint shall be in accordance with Table 6. 4.42 The perpendicularity tolerance of the planes of the two ends of the expansion joint and the axis of the expansion joint shall be in accordance with Table 6. 44.3 The coaxiality tolerance of the two end surfaces of the expansion joint shall be in accordance with the provisions of Table 6. Table 6
Nominal diameter DN
Roundness tolerance
Vertical tolerance
Coaxiality tolerance
4.5 Rigidity
≤500
>500~800
1%DN and less than or equal to 4
>800~1200
>1200~1800
>1200~1600
1%DN and less than or equal to 3
1%DN and not more than 10
>1800~2000
>1600~2000
The stiffness of the expansion joint is calculated according to the formula specified in A2.4.1 and A3-3 of GB/T12777 as the given value. The deviation between the actual average stiffness value of the product (within the total compensation) and the calculated value shall not exceed 30%. 4-6 Safety pressure
JB/T6171-92
The expansion joint shall withstand 1.5 times the nominal pressure at the selected working temperature without damage. 47 Leakage
The expansion joint shall not leak under the specified test pressure conditions. 48 Air tightness
When the working medium of the expansion joint is flammable, explosive and toxic substances, air tightness should be ensured. 49 Stability
491 Planar stability
The ratio of the wave distance of the expansion joint under the specified test pressure to the wave distance before compression shall not exceed 1·15.492 Axial stability
The expansion joint shall not produce axial instability under the specified test pressure. 4.10 Cycle life
The allowable number of cycles of the expansion joint under the specified nominal pressure, working temperature and total compensation shall meet the requirements of the purchaser. If the purchaser does not make any requirements, the allowable number of cycles (N) is 1000 times. Within the allowable number of cycles, there shall be no leakage, instability and other damage. 5 Test method
5.1 Materials
The materials used for the expansion joint are all accepted according to the material list. If there are special requirements, they shall be inspected according to the requirements agreed by the supply and demand parties. 5-2 Appearance
The appearance inspection of the expansion joint shall be carried out by visual inspection under daylight or artificial lighting. 5.3 Structure
5.3-1 Series parameters
531-1 Dimensions
Use general measuring tools with accuracy that meets the specified limit deviation requirements. 5.3-1-2 Total compensation
The total compensation test of the expansion joint is carried out simultaneously with the cycle life test of Article 5.10. 532 Welding
The weld of the expansion joint is generally inspected by visual inspection. If there are special requirements, follow the provisions of Article 108 and Appendix H of GB150 and the drawings. 5.4 Shape and position tolerance
5.4-1 The roundness error inspection of the pipe openings at both ends of the expansion joint shall be carried out according to the method of item 3 in table 19 of GB1183. 5.42 The verticality error inspection of the two end faces of the expansion joint and the axis of the expansion joint shall be carried out according to the method of item 8 in table 19 of GB1183. 5.43 The coaxiality error inspection of the two end faces of the expansion joint shall be carried out according to the method of item 10 in table 19 of GB1183. 5.5 Stiffness
The stiffness test of the expansion joint shall be carried out in accordance with the provisions of Articles 5-8 of GB/T12777. 5.6 Safety pressure
a The pressure test shall use two calibrated pressure gauges with the same range. The range of the pressure gauge should be about 2 times the test pressure, but should not be less than 1.5 times the test pressure.
b The test liquid is water. For austenitic stainless steel materials, the chloride ion content of water should be controlled not to exceed 25ppm. C The test pressure is as follows:
P,=1-5P-
Where: Pt-a test pressure, MPa:
P-nominal pressure of internal pressure or external pressure, MPa; [α) allowable stress of bellows material at test temperature, MPa; 9
JB/T617192
[α)-allowable stress of bellows material at working temperature, MPa. d. The expansion joint is kept in free length state, and the test is carried out at an ambient temperature of 5°C or above. During the test, the pressure should rise slowly, and the pressure should be maintained for 10mln after reaching the specified test pressure. After the test, it should comply with the provisions of Article 46. 5.7 Leakage
The leakage test can be carried out by hydraulic pressure and pneumatic pressure. You can choose either one of them during the test. Hydraulic test: The test pressure is 1-25 times the nominal pressure, and the test requirements are in accordance with Articles 5-6. Air pressure test: If the nominal pressure of the expansion joint is <0-25MPa, the test pressure is 0-25MPa air pressure; if the nominal pressure of the expansion joint is >0-6MPa, the test pressure is 0-5MPa air pressure, and after maintaining the pressure for 5mln, it should comply with the provisions of Article 47. 5-8 Air tightness
The expansion joint can be tested for air tightness only after the safety pressure test. During the test, the expansion joint should maintain its free length, and the test pressure is 1-05 times the nominal pressure. During the test, the pressure should rise slowly, and after reaching the specified test pressure, the pressure should be maintained for 10mln, and then reduced to the nominal pressure, and all welds and joints should be inspected.
5.9 Stability
The expansion joint is kept in a free length state, the test pressure is 1.5 times the nominal pressure, and the test medium is water. The wave distance of each part of the bellows should be measured before the test.
During the test, the pressure should be gradually increased, and after reaching the test pressure, the maximum wave distance of the bellows should be measured. After the test, it should comply with Article 49. 5-10 Cycle life
The cycle life test of the expansion joint can be carried out at room temperature. The test pressure is the nominal pressure, the cyclic displacement is the total compensation amount, and the selection of the cycle rate should ensure that each wave is uniformly deformed. The number of fatigue cycles of the tested expansion joint should comply with Article 410. 6 Inspection rules
Inspection is divided into factory inspection and type inspection.
6.1 Factory inspection
Expansion joints shall be inspected and qualified by the quality inspection department before they can be shipped. 6-1-1 Factory inspection items
Factory inspection items are shown in Table 7.
Unqualified types
Factory inspection items
Safety pressure
Verticality
Coaxiality
Technical requirements Article number
Note: If there is a requirement for air tightness, the air tightness test can be used instead of the leakage test. 6-1-2 Sampling plan
Test method Article number
5·3-2
Qualified quality level AQL
Expansion joints shall be inspected according to the normal inspection sampling plan of GB2828 and the qualified quality level (AQL) value shall be inspected according to the provisions of Table 7. If the production batch is less than or equal to the number of samples for random inspection, the whole batch shall be inspected. 103-1-2 Total compensation
The total compensation test of the expansion joint is carried out at the same time as the cycle life test in Article 5.10. 532 Welding
The weld of the expansion joint is generally inspected by visual inspection. If there are special requirements, it shall be in accordance with Article 108 and Appendix H of GB150 and the provisions of the drawings. 5.4 Shape and position tolerance
5.4-1 The roundness error inspection of the pipe openings at both ends of the expansion joint shall be carried out in accordance with the method of item 3 in table 19 of GB1183. 5.42 The verticality error inspection of the two end faces of the expansion joint and the axis of the expansion joint shall be carried out in accordance with the method of item 8 in table 19 of GB1183. 5.43 The coaxiality error inspection of the two end faces of the expansion joint shall be carried out in accordance with the method of item 10 in table 19 of GB1183. 5.5 Stiffness
The stiffness test of the expansion joint shall be carried out in accordance with the provisions of Articles 5-8 of GB/T12777. 5.6 Safety pressure
a The pressure test must use two calibrated pressure gauges with the same range. The range of the pressure gauge should be about 2 times the test pressure, but should not be less than 1.5 times the test pressure.
b The test liquid is water. For austenitic stainless steel materials, the chloride ion content of water should be controlled not to exceed 25ppm. C The test pressure is as follows:
P,=1-5P-bZxz.net
Where: Pt-a test pressure, MPa:
P-nominal pressure of internal pressure or external pressure, MPa; [α] allowable stress of bellows material at test temperature, MPa; 9
JB/T617192
[α]-allowable stress of bellows material at working temperature, MPa. d. The expansion joint is kept in free length state and the test is carried out at an ambient temperature above 5℃. The pressure should rise slowly during the test and maintain the pressure for 10mln after reaching the specified test pressure. After the test, it should comply with the provisions of Article 46. 5.7 Leakage
The leakage test can be carried out by hydraulic pressure or pneumatic pressure. You can choose either one of them during the test. Hydraulic test: The test pressure is 1-25 times the nominal pressure, and the test requirements are in accordance with Articles 5-6. Air pressure test: If the nominal pressure of the expansion joint is <0-25MPa, the test pressure is 0-25MPa air pressure; if the nominal pressure of the expansion joint is >0-6MPa, the test pressure is 0-5MPa air pressure, and after maintaining the pressure for 5mln, it should comply with the provisions of Article 47. 5-8 Air tightness
The expansion joint can be tested for air tightness only after the safety pressure test. During the test, the expansion joint should maintain its free length, and the test pressure is 1-05 times the nominal pressure. During the test, the pressure should rise slowly, and after reaching the specified test pressure, the pressure should be maintained for 10mln, and then dropped to the nominal pressure, and all welds and joints should be inspected.
5.9 Stability
The expansion joint is kept in free length state, the test pressure is 1.5 times the nominal pressure, and the test medium is water. The wave distance of each part of the bellows should be measured before the test.
During the test, the pressure should be gradually increased. After reaching the test pressure, the maximum wave distance of the bellows is measured. After the test, it should comply with the provisions of Article 49. 5-10 Cycle life
The cycle life test of the expansion joint can be carried out at room temperature. The test pressure is the nominal pressure, the cyclic displacement is the total compensation, and the selection of the cycle rate should ensure that each wave is uniformly deformed. The number of fatigue cycles of the tested expansion joint should comply with the provisions of Article 410. 6 Inspection rules
Inspection is divided into factory inspection and type inspection.
6.1 Factory inspection
The expansion joint shall be inspected and qualified by the quality inspection department before it can be shipped. 6-1-1 Factory inspection items
The factory inspection items are shown in Table 7.
Type of non-conformity
Factory inspection items
Safety pressure
Verticality
Coaxiality
Technical requirements Article number
Note: If there is a requirement for air tightness, the air tightness test can be used instead of the leakage test. 6-1-2 Sampling plan
Test method Article number
5·3-2
Qualified quality level AQL
Expansion joints are inspected according to the normal inspection level II of the sampling plan in GB2828, and the qualified quality level (AQL) value is inspected according to the provisions of Table 7. If the production batch is less than or equal to the number of samples for random inspection, the whole batch shall be inspected. 103-1-2 Total compensation
The total compensation test of the expansion joint is carried out at the same time as the cycle life test in Article 5.10. 532 Welding
The weld of the expansion joint is generally inspected by visual inspection. If there are special requirements, it shall be in accordance with Article 108 and Appendix H of GB150 and the provisions of the drawings. 5.4 Shape and position tolerance
5.4-1 The roundness error inspection of the pipe openings at both ends of the expansion joint shall be carried out in accordance with the method of item 3 in table 19 of GB1183. 5.42 The verticality error inspection of the two end faces of the expansion joint and the axis of the expansion joint shall be carried out in accordance with the method of item 8 in table 19 of GB1183. 5.43 The coaxiality error inspection of the two end faces of the expansion joint shall be carried out in accordance with the method of item 10 in table 19 of GB1183. 5.5 Stiffness
The stiffness test of the expansion joint shall be carried out in accordance with the provisions of Articles 5-8 of GB/T12777. 5.6 Safety pressure
a The pressure test must use two calibrated pressure gauges with the same range. The range of the pressure gauge should be about 2 times the test pressure, but should not be less than 1.5 times the test pressure.
b The test liquid is water. For austenitic stainless steel materials, the chloride ion content of water should be controlled not to exceed 25ppm. C The test pressure is as follows:
P,=1-5P-
Where: Pt-a test pressure, MPa:
P-nominal pressure of internal pressure or external pressure, MPa; [α] allowable stress of bellows material at test temperature, MPa; 9
JB/T617192
[α]-allowable stress of bellows material at working temperature, MPa. d. The expansion joint is kept in free length state and the test is carried out at an ambient temperature above 5℃. The pressure should rise slowly during the test and maintain the pressure for 10mln after reaching the specified test pressure. After the test, it should comply with the provisions of Article 46. 5.7 Leakage
The leakage test can be carried out by hydraulic pressure or pneumatic pressure. You can choose either one of them during the test. Hydraulic test: The test pressure is 1-25 times the nominal pressure, and the test requirements are in accordance with Articles 5-6. Air pressure test: If the nominal pressure of the expansion joint is <0-25MPa, the test pressure is 0-25MPa air pressure; if the nominal pressure of the expansion joint is >0-6MPa, the test pressure is 0-5MPa air pressure, and after maintaining the pressure for 5mln, it should comply with the provisions of Article 47. 5-8 Air tightness
The expansion joint can be tested for air tightness only after the safety pressure test. During the test, the expansion joint should maintain its free length, and the test pressure is 1-05 times the nominal pressure. During the test, the pressure should rise slowly, and after reaching the specified test pressure, the pressure should be maintained for 10mln, and then dropped to the nominal pressure, and all welds and joints should be inspected.
5.9 Stability
The expansion joint is kept in free length state, the test pressure is 1.5 times the nominal pressure, and the test medium is water. The wave distance of each part of the bellows should be measured before the test.
During the test, the pressure should be gradually increased. After reaching the test pressure, the maximum wave distance of the bellows is measured. After the test, it should comply with the provisions of Article 49. 5-10 Cycle life
The cycle life test of the expansion joint can be carried out at room temperature. The test pressure is the nominal pressure, the cyclic displacement is the total compensation, and the selection of the cycle rate should ensure that each wave is uniformly deformed. The number of fatigue cycles of the tested expansion joint should comply with the provisions of Article 410. 6 Inspection rules
Inspection is divided into factory inspection and type inspection.
6.1 Factory inspection
The expansion joint shall be inspected and qualified by the quality inspection department before it can be shipped. 6-1-1 Factory inspection items
The factory inspection items are shown in Table 7.
Type of non-conformity
Factory inspection items
Safety pressure
Verticality
Coaxiality
Technical requirements Article number
Note: If there is a requirement for air tightness, the air tightness test can be used instead of the leakage test. 6-1-2 Sampling plan
Test method Article number
5·3-2
Qualified quality level AQL
Expansion joints shall be inspected according to the normal inspection sampling plan of GB2828, and the qualified quality level (AQL) value shall be inspected according to the provisions of Table 7. If the production batch is less than or equal to the number of samples for random inspection, the whole batch shall be inspected. 10
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