JB/T 5911-1991 Technical requirements for welding parts of electrostatic precipitator JB/T5911-1991 standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB5911-91
Technical requirements for welding parts of electrostatic precipitator
Published on December 25, 1991
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on October 1, 1992
Mechanical Industry Standard of the People's Republic of China
Technical requirements for welding parts of electrostatic precipitator
1 Subject content and scope of application
This standard specifies the design requirements, process requirements, quality assessment and inspection rules for welding parts of electrostatic precipitator. This standard applies to welding parts of electrostatic precipitator made of low carbon steel and ordinary low alloy steel. 2 Reference standards
ZBJ88001.1
JB5910
JB5908
3 Classification of welded parts
Methods of expressing weld symbols
Basic types and sizes of weld grooves for gas welding, manual arc welding and gas shielded welding Basic types and sizes of weld grooves for submerged arc welding Electrostatic precipitator terminology
Technical conditions for electrostatic precipitator
Specifications for sampling inspection, packaging, transportation and storage of main parts of electrostatic precipitator JB5911-91
3.1 General load-bearing parts: inlet head, outlet head, ash hopper, lean-to, manhole door, dust walkway, airflow distribution device, etc. and other parts and components not to be specified.
3.2 Important load-bearing parts: beams, columns, top and side seals, bottom beams, cathode and anode systems, steel brackets, ladder platforms, supports, etc. 4 Design requirements
4.1 Requirements for welded joints
4.1.1 Requirements for welded joints shall be indicated in the design documents, and the weld code shall comply with the provisions of GB324. 4.1.2 The basic types and dimensions of welded joints shall comply with the provisions of GB985 and GB986. 4.2 Tolerance requirements for welded parts
4.2.1 Length tolerance shall comply with the provisions of JB5910. 4.2.2 Angular deviation
The deviations of marked and unmarked angles are shown in Table 1. The nominal size of the angular deviation is based on the short side as the reference side, and its length is measured from the reference point indicated in the drawing as shown in Figure 1.
4.2.3 Geometric toleranceswww.bzxz.net
4.2.3.1 Geometric tolerances of important welds (cross-sectional direction) shall comply with the provisions of Table 2. 4.2.3.2 Geometric tolerances of important welds (length direction) shall comply with the provisions of JB5910. 4.2.3.3 The manufacturing tolerances of plate structural parts, the diagonal tolerances and plate surface flatness are shown in Figure 2 and Table 3. 4.3 Weld quality requirements
4.3.1 The surface quality requirements of butt welds are shown in Table 4. 4.3.2 The surface quality requirements of fillet welds and T-welds are shown in Table 5. 4.3.3 The internal quality requirements of butt welds, fillet welds and T-welds are shown in Table 6. Mechanical Approved by the Ministry of Electronics Industry on December 25, 1991 and implemented on October 1, 1992
Inspection items
Aa=20°
JB591191
4a=10°
4≤0.016 and
Inspection items date
Web
JB5911-91
Continued Table 2
H≤500
lal≤3
4≤0.01b and
When beam length≤5000
When beam length>5000
4≤0.016 and|| tt||Diagonal length
700~2000
(2000)～5000
(5000)～9000
(9000)~13000
5 Process requirements
5.1 Preparation before welding
JB5911-91
Plane flatness 4B
5.1.1 Before welding, the surface dirt of the weldment (for manual arc welding and automatic welding, the distance from the edge shall not be less than 10mm) shall be removed in advance. 5.1.2 For the initial correction of steel and the forming and bending of steel, see Appendix A (supplement), diagonal tolerance △
5 .1.3 The welding groove can be planed out with a planer or cut out with gas cutting. When gas cutting, the burrs, cracks, slag and uneven places on the edge should be cleaned. 5.1.4 Forced assembly should be avoided when assembling welded parts. The allowable assembly deviation and measurement method are shown in Table 7. 5.2 Welding method
Manual arc welding, carbon dioxide gas shielded welding, submerged arc automatic welding, gas welding, resistance welding and other welding methods can be selected. 5.3 Requirements for welding materials
5.3.1 Welding materials (welding rods, welding wires, and fluxes should have a certificate of conformity from the manufacturer. Welding materials of unknown brands shall not be used. 5.3.2 There shall be no rust or oil stains on the surface of the welding wire. The flux shall be stored in a sealed container. The damp flux should be dried before use. 5.4 Environmental requirements
When any steel structure is operated outdoors, welding shall not be carried out in rainy, snowy or heavy rain. Cracks
Incomplete penetration
JB591191
Welding parts categories
General load-bearing parts
Not allowed
Important load-bearing parts
The length of the undercut shall not exceed 1.5% of the length of the weld and its depth shall not exceed the following provisions:
8≤10, 40.5, 8>40, A≤1.5
8>10, A≤1.0
Not allowed Allowed
Partially allowed, but the root bulge must be uniform and smooth, and have a smooth transition with the parent material
Not allowed
Partially allowed
A≤0.2(1+0.18)
But the maximum is 0.5
A≤1+0.25B
A≤1+0.15B
Single-sided misalignment
Double-sided misalignment
Surface defects
Root defects
Weld height difference
Weld discontinuity
JB5911-91
Continued Table 4
General load Parts
A≤0.158
but maximum A-2
but maximum A=3
Single defect diameter
Welding part category
D≤0.18, but maximum D≤1.5,
A piece of defect area F<10mm
but maximum 1
A small amount of spatter is allowed
Not allowed
Important load-bearing parts
but maximum A=1.5
A≤0.158
but maximum A=2
Single defect diameter
D≤0.18, but maximum D ≤1.5,
defect area of ​​sheet F<5mm
A≤0.058
but the maximum is 0.5
not allowed
weld angle deviation
root defect
JB5911—91
weld part category
general load-bearing parts
not allowed
important load-bearing parts
undercut length does not exceed 1.5% of weld length and its depth does not exceed the following provisions:
>10,A≤1.0
8>40,A≤1.5
K<6,4K=+1. 0
K≤14.△Km
K>14, AK=
A<1+0.15K, but the maximum is 3,
local small protrusions are allowed
not allowed
A≤1+0.1K
but the maximum is 2
surface defects
weld height difference
lack of fusion
lack of fusion
JB5911—91
Continued Table 5
weldment category
general load-bearing parts
allowed, but no cracks
single defect diameter
important load-bearing parts
not allowed| |tt||D≤0.18, but the maximum D1.5, a defect area F≤10mm, a small amount of spatter is allowed
AH≤3
Welding parts category
General load-bearing parts
Not allowed
A≤0.28, but the maximum is 4, and L≤8, the unfused part cannot reach the surface
A≤0.28, the maximum is 2, and L≤28,
Cannot be within the range of 100
from the end of the weld
Not allowed
AH≤2
Important load-bearing parts
Not allowed
A≤0.16. The maximum is 2, and L≤
0.48, cannot be within 100 from the end of the weld
Various internal defect combinations
Inspection items
T-joint
Root image
Lap joint
Groove weld
Butt joint
Deviation
JB5911—91
Continued Table 6
General load Parts
Single pore diameter is less than 0.36, the maximum
is 4, the total pore area is less than 40mm
Single slag inclusion L≤28, but the maximum is 50,
Total length of scattered slag inclusions≤38, but the maximum is
Total defect area
≤0.8/100mm
Allowable deviation
When e>1.6, fillet weld
The weld leg of the seam should increase with the increase of e
Measuring device
Weld gauge
Important load-bearing parts
The diameter of a single pore is less than 0.28, the maximum
is 3, and the total pore area is less than 28mm
Single slag inclusion L≤0.48, but the maximum is
20, the total length of scattered slag inclusions ≤26, but the maximum is 50
Total defect area
0.48/100mm2
Measurement method
Inspection items
Root spacing of joint without backing plate
Root spacing of joint with backing plate
Blunt edge of joint
Groove surface angle
Groove angle
Groove angle
6 Inspection
a± Aa
JB5911-91
Continued Table 7
Allowable deviation
Manual arc welding:
Uncut edge root
Cutting edge root
1.6≤e<3.2
Submerged arc welding:
Uncut edge root
0
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