JB/T 6895-1993 Technical specification for installation and welding of aluminum air separation equipment
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T 6895-1993
Technical Specification for Installation Welding of Aluminum Air Separation Equipment Issued on July 13, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on July 1, 1994
Subject Content and Scope of Application
Cited Standards
Basic Requirements for Installation Units
Welding Filling Materials
Welding Procedure Qualification
Test Specimen, Test and Qualified Value Evaluation
Product Test Plate
Assembly Welding of Upper Tower and Main Condenser
Arrangement and Groove Type of Aluminum Pipe Weld|| tt||Post-weld inspection of aluminum pipeline welds
Evaluation of X-ray radiographic film grade of aluminum welds Appendix A
Appendix B
Aluminum air separation equipment Aluminum pipeline welding joint groove type, characteristics and applicable scope 13
Machinery Industry Standard of the People's Republic of China
Aluminum air separation equipment installation welding technical specification 1 Subject content and applicable scope
JB/T6895-1993
This standard specifies the welding technical requirements and inspection requirements that must be followed for pipelines and containers manufactured and installed on-site of aluminum air separation equipment (hereinafter referred to as air separation equipment).
This standard applies to the installation welding of aluminum air separation equipment. 2
Reference standards
JB1580
JB4708
JB/Z167
Steel pressure vessels
Metal tensile test method
Metal bending test method
Technical conditions for aluminum welded vessels
Welding process assessment for steel pressure vessels
Argon arc welding process specification for aluminum air separation equipment 3 Basic requirements for installation units
3.1 The installation unit responsible for on-site production and assembly of pressure vessels must hold a pressure vessel manufacturing license of the corresponding category and type approved by the labor department.
3.2 A welding quality assurance system should be established and implemented effectively. 3.3 It should have intact welding equipment and non-destructive testing equipment that can meet the installation needs (metallographic and mechanical property tests can be entrusted to external units).
3.4 There should be full-time welding technicians who can provide technical guidance to welders, have strong sense of responsibility and good professional quality. 3.5
There should be welders and non-destructive flaw detectors who can adapt to the installation needs and have obtained the corresponding qualification certificates after training and examination. 3.6
There should be welding inspectors who are competent for the job. There should be necessary wind (electric) power tools. 3.7
There should be windproof, rain (snow) protection facilities and measures for welding when the ambient temperature is below -5℃. 4 Materials
4.1 The materials, finished products or semi-finished products provided by the manufacturer shall be the responsibility of the manufacturer. When the manufacturer implements material substitution, it shall be noted on the completion drawing and a conspicuous material mark shall be stamped (or engraved) on the substitute material, or the user shall be informed of the material after substitution through other means. 4.2 The installation unit must check the material before welding. Workpieces or materials whose materials cannot be determined shall be scrapped. Scrapped materials or workpieces should be marked with eye-catching signs and isolated.
4.3 The materials prepared by the installation company should comply with the requirements of the drawings and technical documents. The materials should be the responsibility of the installation unit. Approved by the Ministry of Machinery Industry on July 13, 1993
Implementation on July 1, 1994
JB/T 6895-1993
4.4 If the pressure components of the container or the pressure pipeline are to be replaced, the consent of the design unit must be obtained and a change notice must be issued.
The storage area for materials and parts should have rain (snow) and corrosion protection facilities, and measures should be taken to prevent bumps and scratches during lifting and transportation.
5 If the material is thinned by no more than 0.5mm due to bumps and corrosion, grinding can be used to remove the defects. If it exceeds 0.5mm, 4. 6
Welding repair should be carried out using a qualified welding process, and after welding repair, it should be polished and color checked to be qualified. 5
Welding filler materials
5.1 Welding filler materials should have a quality certificate from the manufacturer and meet the corresponding standards. 5.2 There are three requirements for aluminum welding filler materials. 5.2.1
The selection of aluminum welding wire should comply with the provisions of Table 1. Otherwise, the manufacturer's consent should be obtained and the welding process should be qualified. Table 1
Welding filler materials
LF2+LF2
LF11 or
SAIMg-5
LF2+LF21
LF11 or
SAIMg-5
LF21+LF21
LF21 or
LF4+LF4
LF4+LF2
SAIMg-3
LF4+LF21
When two or more welding wires are used, one end of the manual tungsten inert gas welding (hereinafter referred to as TIG) wire shall be painted with color 5.2.2
paint to mark the difference. The color shall be determined by the installation unit. Argon arc welders can only use one brand and different specifications of welding wire at a time. TIG welding wire shall be placed in the welding wire tube and kept clean and dry. 5.2.3 Unless the welding wire has been cleaned, dried and sealed, it must be degreased, cleaned and dried before use. 5.3 Ferrous metal welding filler materials shall be implemented in accordance with the drawings and relevant regulations. 6 Welders
6.1 Welders who are responsible for the installation and welding of pressure pipes and pressure-bearing components of vessels must pass the basic knowledge and operating skills examination and obtain the corresponding project certificate.
Ferrous metal welder examination shall be implemented in accordance with the Ministry of Labor & Boiler Pressure Vessel Welder Examination Rules: Aluminum argon arc welders shall be implemented in accordance with this standard. 6.2 The training and examination of welders shall be organized and implemented by the welder examination committee approved by the labor department of the unit. Units that do not have the conditions to establish a welder examination committee may entrust qualified units to conduct training and examinations on their behalf. The standards and examination results based on the examination shall be filed with the local labor department.
6.3 The welding process used in the welder examination shall first be qualified by the welding process assessment. When the qualified welding process is used for the examination, if only the non-basic parameters (see Chapter 7 for details) are changed, there is no need to re-evaluate the process. 6.4 Welders must pass the basic knowledge test before they can take the operation skill test. The material knowledge in the basic knowledge test requirements for argon arc welders should focus on non-ferrous metals, and the welding process, methods, equipment, welding defects and other contents should focus on argon arc welding. 6.5 The aluminum argon arc welder examination should comply with the following regulations. 6.5.1 When the following conditions change, the welder must retake the operation skill test Change of welding method: Tungsten inert gas arc welding (TIG) is changed to metal inert gas arc welding (MIG) (including automatic or semi-automatic) or vice versa.
; Metal inert hydrogen arc welding is changed to semi-automatic argon arc welding or vice versa; single-person TIG welding is changed to double-sided two-person simultaneous TIG welding or vice versa: 2
JB/T6895-1993
b. Changes in welding joint types: butt joints to fillet joints or vice versa: no gasket to gasket (aluminum or embedded stainless steel gasket) or vice versa;
Changes in welding position: except for the range specified in Table 2 to Table 6, changes in welding position should be retested. 6.5.2
When the following conditions change, the welder does not need to retest the operation skills a.
Change in parent material, that is, from one aluminum or aluminum alloy to another aluminum or aluminum alloy; change in the outer diameter of the pipe;
Change in groove parameters (blunt edge, gap, groove angle); d.
Change in parent material thickness or deposited metal thickness; e.
Change from single-sided welding to double-sided welding.
All exploration operation skills tests should be single-sided welding (excluding consumable argon arc welding and double-sided two-person welding at the same time). After passing the single-sided welding test 6.5.3
, the welder can be responsible for single-sided welding or double-sided welding. All operation skill tests shall be conducted on the basis of passing the TIG-1-flat welding test. 6.5.4
The manual tungsten inert gas fluorine arc welding test plate (or pipe) shall be interrupted at least once during the welding process. The double-sided two-person vertical welding (or horizontal welding) test piece shall have at least two positioning point welds in the entire weld length direction. Before horizontal fixed welding of tubular test pieces, the welding position should be marked with the hour mark according to the clock position. The positioning point weld should not be in the overhead welding position and its length should not be greater than 15mm. 6.5.8
Flat plate butt test pieces are allowed to use lead-in plates and lead-out plates. Except for the positioning point weld, which is allowed to be ground, re-welded or welded, the inner and outer surfaces of the weld shall not be ground or welded, but grinding and cleaning between layers are allowed. For single-sided welding and double-sided forming test pieces, if the base layer is not welded through, the base layer weld is ground thin and re-welded until it is welded through, which shall be regarded as a failure in the test. 6.5.10 The welding position of the test piece shall not be changed during the test. 6.5.11
A welder who passes the test will be issued a steel stamp. The installation unit shall establish welder files and welding quality records, and calculate the weld repair rate and scrap rate on a monthly basis, which will serve as the basis for exempting welders from the test, revoking the qualification certificate, and deciding whether to expand the X-ray photography inspection rate of the installation welds. The repair rate is calculated according to formula (1): weld repair rate =
total length of repaired welds
total length of filmed welds (i.e. total length of film). (1)
3 If a welder fails the practical operation skill test, he/she is allowed to take a retest once within a short period of time. If he/she still fails the retest, he/she must undergo training for no less than two weeks before applying for a retest. 6.5.14 If the welding work of aluminum pressure vessels or pipelines is interrupted for 6 consecutive months, the corresponding qualified items will be invalid. A corresponding retest should be conducted before welding work is resumed.
6.5.15 The welder's qualified items are valid for 3 years. If it exceeds 3 years, a retest is required. 6.5.16 For welders with consistently good welding quality, their units shall provide their quality indicators, which shall be verified by the quality inspection department, reviewed and approved by the welder examination committee, and reported to the local labor department for record. They may be exempted from re-examination and the validity period shall be extended for another 3 years, but they shall not be exempted from re-examination twice in a row. For welders with poor welding quality, the quality inspection department shall provide their quality indicators, and the welder examination committee shall have the right to revoke their certificates and report them to the local labor department for record.
6.5.17 The operation skill examination items are shown in Tables 2 to 7. For products with special welding positions, materials or structures, the examination items and requirements can be set by the examination committee to simulate the actual products. 3
Lead-out plate
Inspection and test requirements
Requirements and explanations
Applicable scope
≥220
JB/T 6895-1993
Project code: TIG-1-Flat welding
Lead-in plate
Not required
1. Welding method: Single-layer single-sided welding
2. Welding position: Horizontal
Test piece type
X-ray photography
Single-sided or double-sided flat welding of aluminum plate, horizontal rotation welding of aluminum tube
Not required
Not required
Inspection and test requirements
Requirements and explanations
Scope of application
JB/T 6895-1993
Project code: TIG-6-horizontal fixation: TIC-7-vertical fixationTest piece type
Not required
Not required
1.Welding method: TIG single-layer single-sided welding
2.Welding position: TIG-6
TIG-7-
All positions
TIG-6-horizontal fixation qualified can be used for pipeline all-position weldingTIG-7-vertical fixation qualified can be used for plate or pipe horizontal weldingX-ray photography
Not required
2 for each welding position|| tt||Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-8-horizontal rotation; TIC-9-horizontal fixation: TIG-10-vertical fixationTest piece type
Not required
Not required
X-ray photography
1.Welding method: TIG single-sided welding, welding layer is not less than 2 layers
Not required
(2 test pieces for each welding position)
2.Welding position; TIG-8 Horizontal, TIG-9 full position, TIG-10 horizontal welding 3. If aluminum permanent gaskets are used in the actual installation, aluminum gaskets are also used in the test. The test requirements are the same, but the bending test is exempted.
4. The bending test should be carried out after the gaskets are ground (or chiseled) off. After passing the TIG-9-horizontal fixation or TIG-10-vertical fixation, the TIG-8-horizontal rotation test can be exempted, otherwise it is not. Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-4-double-sided vertical Welding
Test piece type
Requirements (2 test pieces)
Not required
X-ray photography
1. Welding method: TIG welding by two people on both sides at the same time, 1 layer of welding 2. Welding position: vertical welding
Not required
Not required
3. There should be at least two positioning spot welds along the entire weld length, and the positioning weld should also be two people on both sides at the same time vertical welding. After this project is qualified, it is applicable to the two-sided two-person vertical welding of butt or fillet joints. Inspection and test requirements
Requirements and instructions
Scope of application
JB/T 6895-1993
Project code: TIG-11-Flat fillet weld
Specimen type
Not required
X-ray photography
1. Welding method: Manual TIG welding, number of welds: 1 layer2. Welding position: Flat fillet weld
3. Positioning spot welds at both ends of the specimen
Not required
Not required
Don't 4. Fracture inspection method: Clamp the 145×80×8 plate in the bench vise, use a hammer to knock off the two 80×60X8 plates in the direction of the arrow in the figure above, and then check the fracture. Applicable to the welding of the corner joints of plate + tube, plate + plate or tube + tube. Inspection and test requirements. Requirements and instructions. Scope of application. JB/T6895-19 93
Project code: TIG-12-Double-sided horizontal welding
Test piece type
Prohibited items
Requirements (2 test pieces)
Not required
X-ray photography
1. Welding method: Manual TIG double and two people welding at the same timeNumber of welding layers: 6≤
2. Welding position; when horizontal welding
, it is layer:
3. Test piece thickness 5 is determined by the actual thickness of the product4. Positioning spot welding should also adopt two people two sides at the same time horizontal weldingBend
Not required
Not required
Applicable to double-sided two people at the same time horizontal welding (mainly for the welding of girth welds when installing the lower tower and the main condenser)6.6 Requirements for test appearance inspection
The weld surface must be in the original state, and the weld edge should smoothly transition to the parent material. The weld surface shall not have defects such as cracks, incomplete penetration, incomplete fusion and weld nodules. Other surface defects shall not exceed the requirements of Table 8. Table 8
Defect name
Back concave
Arc points
Back shrinkage
Maximum allowed size
Depth not more than 0.5mm: Total length of undercut on both sides of the weld: Plate specimens shall not exceed 10% of the total weld length; Tubular specimens shall not exceed 20% of the total weld length
Plate specimens are not allowed, and tubular specimens are allowed to have a concave depth of no more than 0.5mm. No more than 3 pores no larger than 0.5mm are allowed. Arc points outside the weld are unqualified
Shrinkage holes on the back are unqualified
The external dimensions of butt welds shall comply with the requirements of Table 9, and the maximum back penetration height of single-sided welds shall not exceed 4mm. 917 Operational skills test items are shown in Tables 2 to 7. For products with special welding positions, materials or structures, the test items and requirements can be set by the test committee to simulate the actual product. 3
Lead-out plate
Inspection and test requirements
Requirements and explanations
Applicable scope
≥220
JB/T 6895-1993
Project code: TIG-1-Flat welding
Lead-in plate
Not required
1. Welding method: Single-layer single-sided welding
2. Welding position: Horizontal
Test piece type
X-ray photography
Single-sided or double-sided flat welding of aluminum plate, horizontal rotation welding of aluminum tube
Not required
Not required
Inspection and test requirements
Requirements and explanations
Scope of application
JB/T 6895-1993
Project code: TIG-6-horizontal fixation: TIC-7-vertical fixationTest piece type
Not required
Not required
1.Welding method: TIG single-layer single-sided welding
2.Welding position: TIG-6
TIG-7-
All positions
TIG-6-horizontal fixation qualified can be used for pipeline all-position weldingTIG-7-vertical fixation qualified can be used for plate or pipe horizontal weldingX-ray photography
Not required
2 for each welding position|| tt||Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-8-horizontal rotation; TIC-9-horizontal fixation: TIG-10-vertical fixationTest piece type
Not required
Not required
X-ray photography
1.Welding method: TIG single-sided welding, welding layer is not less than 2 layers
Not required
(2 test pieces for each welding position)
2.Welding position; TIG-8 Horizontal, TIG-9 full position, TIG-10 horizontal welding 3. If aluminum permanent gaskets are used in the actual installation, aluminum gaskets are also used in the test. The test requirements are the same, but the bending test is exempted.
4. The bending test should be carried out after the gaskets are ground (or chiseled) off. After passing the TIG-9-horizontal fixation or TIG-10-vertical fixation, the TIG-8-horizontal rotation test can be exempted, otherwise it is not. Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-4-double-sided vertical Welding
Test piece type
Requirements (2 test pieces)
Not required
X-ray photography
1. Welding method: TIG welding by two people on both sides at the same time, 1 layer of welding 2. Welding position: vertical welding
Not required
Not required
3. There should be at least two positioning spot welds along the entire weld length, and the positioning weld should also be two people on both sides at the same time vertical welding. After this project is qualified, it is applicable to the two-sided two-person vertical welding of butt or fillet joints. Inspection and test requirements
Requirements and instructions
Scope of application
JB/T 6895-1993
Project code: TIG-11-Flat fillet weld
Specimen type
Not required
X-ray photography
1. Welding method: Manual TIG welding, number of welds: 1 layer2. Welding position: Flat fillet weld
3. Positioning spot welds at both ends of the specimen
Not required
Not required
Don't Request
4. Fracture inspection method: Clamp the 145×80×8 plate in the bench vise, use a hammer to knock off the two 80×60X8 plates in the direction of the arrow in the figure above, and then check the fracture
Applicable to the welding of the corner joints of plate + tube, plate + plate or tube + tube
Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-19 93
Project code: TIG-12-Double-sided horizontal welding
Test piece type
Prohibited items
Requirements (2 test pieces)
Not required
X-ray photography
1. Welding method: Manual TIG double and two people welding at the same timeNumber of welding layers: 6≤
2. Welding position; when horizontal welding
, it is layer:
3. Test piece thickness 5 is determined by the actual thickness of the product4. Positioning spot welding should also adopt two people two sides at the same time horizontal weldingBend
Not required
Not required
Applicable to double-sided two people at the same time horizontal welding (mainly for the welding of girth welds when installing the lower tower and the main condenser)6.6 Requirements for test appearance inspection
The weld surface must be in the original state, and the weld edge should smoothly transition to the parent material. The weld surface shall not have defects such as cracks, incomplete penetration, incomplete fusion and weld nodules. Other surface defects shall not exceed the requirements of Table 8. Table 8
Defect name
Back concave
Arc points
Back shrinkage
Maximum allowed size
Depth not more than 0.5mm: Total length of undercut on both sides of the weld: Plate specimens shall not exceed 10% of the total weld length; Tubular specimens shall not exceed 20% of the total weld length
Plate specimens are not allowed, and tubular specimens are allowed to have a concave depth of no more than 0.5mm. No more than 3 pores no larger than 0.5mm are allowed. Arc points outside the weld are unqualified
Shrinkage holes on the back are unqualified
The external dimensions of butt welds shall comply with the requirements of Table 9, and the maximum back penetration height of single-sided welds shall not exceed 4mm. 917 Operational skills test items are shown in Tables 2 to 7. For products with special welding positions, materials or structures, the test items and requirements can be set by the test committee to simulate the actual product. 3
Lead-out plate
Inspection and test requirements
Requirements and explanations
Applicable scope
≥220
JB/T 6895-1993
Project code: TIG-1-Flat welding
Lead-in plate
Not required
1. Welding method: Single-layer single-sided welding
2. Welding position: Horizontal
Test piece type
X-ray photography
Single-sided or double-sided flat welding of aluminum plate, horizontal rotation welding of aluminum tube
Not required
Not required
Inspection and test requirements
Requirements and explanations
Scope of application
JB/T 6895-1993
Project code: TIG-6-horizontal fixation: TIC-7-vertical fixationTest piece type
Not required
Not required
1.Welding method: TIG single-layer single-sided welding
2.Welding position: TIG-6
TIG-7-
All positions
TIG-6-horizontal fixation qualified can be used for pipeline all-position weldingTIG-7-vertical fixation qualified can be used for plate or pipe horizontal weldingX-ray photography
Not required
2 for each welding position|| tt||Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-8-horizontal rotation; TIC-9-horizontal fixation: TIG-10-vertical fixationTest piece type
Not required
Not required
X-ray photography
1.Welding method: TIG single-sided welding, welding layer is not less than 2 layers
Not required
(2 test pieces for each welding position)
2.Welding position; TIG-8 Horizontal, TIG-9 full position, TIG-10 horizontal welding 3. If aluminum permanent gaskets are used in the actual installation, aluminum gaskets are also used in the test. The test requirements are the same, but the bending test is exempted.
4. The bending test should be carried out after the gaskets are ground (or chiseled) off. After passing the TIG-9-horizontal fixation or TIG-10-vertical fixation, the TIG-8-horizontal rotation test can be exempted, otherwise it is not. Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-4-double-sided vertical Welding
Test piece type
Requirements (2 test pieces)
Not required
X-ray photography
1. Welding method: TIG welding by two people on both sides at the same time, 1 layer of welding 2. Welding position: vertical welding
Not required
Not required
3. There should be at least two positioning spot welds along the entire weld length, and positioning welding should also be two people on both sides at the same time vertical welding. After this project is qualified, it is applicable to the two-sided two-person vertical welding of butt or fillet joints. Inspection and test requirements
Requirements and instructions
Scope of application
JB/T 6895-1993
Project code: TIG-11-Flat fillet weld
Specimen type
Not required
X-ray photography
1. Welding method: Manual TIG welding, number of welds: 1 layer2. Welding position: Flat fillet weld
3. Positioning spot welds at both ends of the specimen
Not required
Not required
Don't 4. Fracture inspection method: Clamp the 145×80×8 plate in the bench vise, use a hammer to knock off the two 80×60X8 plates in the direction of the arrow in the figure above, and then check the fracture. Applicable to the welding of the corner joints of plate + tube, plate + plate or tube + tube. Inspection and test requirements. Requirements and instructions. Scope of application. JB/T6895-19 93
Project code: TIG-12-Double-sided horizontal welding
Test piece type
Prohibited items
Requirements (2 test pieces)
Not requiredWww.bzxZ.net
X-ray photography
1. Welding method: Manual TIG double and two people welding at the same timeNumber of welding layers: 6≤
2. Welding position; when horizontal welding
, it is layer:
3. Test piece thickness 5 is determined by the actual thickness of the product4. Positioning spot welding should also adopt two people two sides at the same time horizontal weldingBend
Not required
Not required
Applicable to double-sided two people at the same time horizontal welding (mainly for the welding of girth welds when installing the lower tower and the main condenser)6.6 Requirements for test appearance inspection
The weld surface must be in the original state, and the weld edge should smoothly transition to the parent material. The weld surface shall not have defects such as cracks, incomplete penetration, incomplete fusion and weld nodules. Other surface defects shall not exceed the requirements of Table 8. Table 8
Defect name
Back concave
Arc points
Back shrinkage
Maximum allowed size
Depth not more than 0.5mm: Total length of undercut on both sides of the weld: Plate specimens shall not exceed 10% of the total weld length; Tubular specimens shall not exceed 20% of the total weld length
Plate specimens are not allowed, and tubular specimens are allowed to have a concave depth of no more than 0.5mm. No more than 3 pores no larger than 0.5mm are allowed. Arc points outside the weld are unqualified
Shrinkage holes on the back are unqualified
The external dimensions of butt welds shall comply with the requirements of Table 9, and the maximum back penetration height of single-sided welds shall not exceed 4mm. 9Welding method: manual TIG welding, 1 layer 2. Welding position: flat fillet welding
3. Positioning spot welding at both ends of the specimen
Not required
Not required
Not required
4. Fracture inspection method: Clamp the 145×80×8 plate on the bench vise, use a hammer to knock down the two 80×60X8 plates in the direction of the arrow in the figure above, and then check the fracture
Applicable to the welding of corner joints of plate + tube, plate + plate or tube + tube
Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-12-Double-sided horizontal welding
Specimen type
Prohibited items
Requirements (2 specimens)
Not required
X-ray photography
1. Welding method: Manual TIG double and double people welding at the same timeNumber of welding layers: 6≤
2. Welding position; horizontal welding
When the layer is:
3. The thickness of the test piece 5 is determined by the actual thickness of the product4. Positioning spot welding should also be double people double-sided horizontal welding at the same timeBend
Not required
Not required
Applicable to double-sided double people horizontal welding at the same time (mainly for the welding of the girth weld when installing the lower tower and the main condenser composite welding)6.6 Requirements for test appearance inspection
The weld surface must be in the original state, and the weld edge should smoothly transition to the parent material. There must be no defects such as cracks, incomplete penetration, incomplete fusion and weld nodules on the weld surface. Other surface defects shall not exceed the provisions of Table 8. Table 8
Defect name
Back concave
Arc point
Back shrinkage
Maximum allowed size
Depth not more than 0.5mm: Total length of undercut on both sides of weld: Plate specimens not more than 10% of the total length of weld; Tubular specimens not more than 20% of the total length of weld
Plate specimens are not allowed, and tubular specimens are allowed to have a concave depth of no more than 0.5mm. No more than 3 pores no more than 0.5mm are allowed. Arc points outside the weld are unqualified
Shrinkage on the back is unqualified
The external dimensions of the butt weld should comply with the provisions of Table 9, and the maximum height of the back penetration of the single-sided weld should not be more than 4mm. 9Welding method: manual TIG welding, 1 layer 2. Welding position: flat fillet welding
3. Positioning spot welding at both ends of the specimen
Not required
Not required
Not required
4. Fracture inspection method: Clamp the 145×80×8 plate on the bench vise, use a hammer to knock down the two 80×60X8 plates in the direction of the arrow in the figure above, and then check the fracture
Applicable to the welding of corner joints of plate + tube, plate + plate or tube + tube
Inspection and test requirements
Requirements and instructions
Scope of application
JB/T6895-1993
Project code: TIG-12-Double-sided horizontal welding
Specimen type
Prohibited items
Requirements (2 specimens)
Not required
X-ray photography
1. Welding method: Manual TIG double and double people welding at the same timeNumber of welding layers: 6≤
2. Welding position; horizontal welding
When the layer is:
3. The thickness of the test piece 5 is determined by the actual thickness of the product4. Positioning spot welding should also be double people double-sided horizontal welding at the same timeBend
Not required
Not required
Applicable to double-sided double people horizontal welding at the same time (mainly for the welding of the girth weld when installing the lower tower and the main condenser composite welding)6.6 Requirements for test appearance inspection
The weld surface must be in the original state, and the weld edge should smoothly transition to the parent material. There must be no defects such as cracks, incomplete penetration, incomplete fusion and weld nodules on the weld surface. Other surface defects shall not exceed the provisions of Table 8. Table 8
Defect name
Back concave
Arc point
Back shrinkage
Maximum allowed size
Depth not more than 0.5mm: Total length of undercut on both sides of weld: Plate specimens not more than 10% of the total length of weld; Tubular specimens not more than 20% of the total length of weld
Plate specimens are not allowed, and tubular specimens are allowed to have a concave depth of no more than 0.5mm. No more than 3 pores no more than 0.5mm are allowed. Arc points outside the weld are unqualified
Shrinkage on the back is unqualified
The external dimensions of the butt weld should comply with the provisions of Table 9, and the maximum height of the back penetration of the single-sided weld should not be more than 4mm. 9
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