HG/T 20545-1992 Technical requirements for the manufacture of pressure components for chemical industrial furnaces
Some standard content:
Industry Standard of the People's Republic of China
Technical Specification of Shop Fabrication forPressure Parts of Chemical FurnaceHG20545-92
Editor: The Eighth Design Institute of the Ministry of Chemical Industry
Approval Department: Ministry of Chemical Industry
Implementation Date: July 1, 1993
Editorial Center for Engineering Construction Standards of the Ministry of Chemical Industry
1 General Provisions
1.0.1 This technical specification applies to the manufacture, inspection and acceptance of pressure parts of chemical industrial furnaces heated by direct flames. Pressure parts include the following scope:
1.0.1.1 Rolled furnace tubes with design pressure less than or equal to 24MPa and design temperature less than or equal to 900℃, which are welded together by rolled seamless steel pipes and fittings made of carbon steel, alloy steel and stainless heat-resistant steel. 1.0.1.2 Design pressure is less than or equal to 5MPa, design temperature is less than or equal to 1100℃, centrifugally cast furnace tubes welded together by centrifugally cast heat-resistant alloy tubes and pipe fittings. 1.0.1.3 Pipe fittings of carbon steel, alloy steel, stainless heat-resistant steel and heat-resistant alloy cast steel, such as elbows, tees, manifolds, bosses, tapered tubes and flanges.
1.0.2 For pressure cylinder heads and components with refractory lining, such as the second-stage reformer of heavy oil gasifiers, waste heat boiler pipe boxes, etc., except for special requirements in this technical condition, they shall be manufactured, inspected and accepted in accordance with the provisions of GB150. 1.0.3 Related standards or referenced standards
1.0.3.1 Related standards or referenced standards for materials GB9948 "Seamless steel pipes for petroleum cracking" GB8163
"Seamless steel pipes for conveying fluids"
"High-pressure seamless steel pipes for fertilizer equipment"
GB 6479
"Seamless steel pipes for high-pressure boilers"
GB5310
GB3087
GB 2270
"Seamless steel pipes for low and medium pressure boilers"
"Stainless steel seamless steel pipes"
HG5-1557 "Technical conditions for centrifugal casting alloy furnace pipes for high temperature pressure" HGJ 41
HGJ 15
《Design and Selection of Metal Materials for Chemical Industrial Furnaces》《Materials Selection of Steel Chemical Containers》GB8492《Heat-resistant Steel Castings》
2《Casting Carbon Steel Parts for General Engineering》
GB11352
GB2100
《Stainless Acid-resistant Steel Castings》
JB/ZQ4297《Alloy Cast Steel》
JB755《Technical Conditions for Pressure Vessel Forgings》1.0.3.2 Relevant standards or referenced standards for manufacturing GB150《Steel Pressure Vessels》
JB1611《Technical Conditions for Manufacturing Boiler Tubes》CHJB301《Technical Conditions for Manufacturing Harp Pipe Rows for Radiation Sections of One-stage Furnaces》ZBG93010《High-frequency Resistance Welded Spiral Finned Tubes》GB/T113 50 Machining allowance of castings GB6414 Dimensional tolerances of castings
GB1804
Tolerances and fits - limit deviations of dimensions without tolerances 67
Relevant standards or referenced standards for inspection
Radiography and quality grading of steel fusion welded butt joints
Magnetic particle inspection of steel pressure vessels
GB5677
Classification method for radiography and film grade of castings GB6394
Determination method for average grain size of metals
GB10561 Microscopic evaluation method for non-metallic inclusions in steel GB1612 Technical conditions for water pressure test of boilers 68
2.0.1 The materials used to manufacture pressure components of chemical industrial furnaces must have a quality certificate. 2.0.2'The materials used for pressure components of chemical industrial furnaces shall comply with the provisions of HGJ41. 2.0.3 The steel used for pressure cylinders, heads and components with refractory linings shall comply with the relevant provisions of GB150, but at the same time meet the following conditions:
The design temperature is greater than 300℃; the design pressure is greater than or equal to 1.6MPa; the thickness of the steel plate is greater than 16mm; the main section of the steel is mainly used to bear the primary film stress, and its thickness depends on the results of the strength calculation. It should also be re-tested according to the furnace number. The compliant strength value at the design temperature shall not be less than 1.6 times the corresponding allowable stress value (1.5 times for austenitic steel). 69
3.1 Rolled furnace tubes
3.1.1General principles, the manufacture of steam furnace tubes must comply with the provisions of JB1611. The manufacture of non-steam furnace tubes shall comply with the requirements of this technical condition. If the design has higher or special requirements for manufacturing, it should be stated in the drawings or relevant technical documents.
3.1.2 Pipe splicing
3.1.2.1 For vertical furnace tubes, it is advisable to use whole tubes for manufacturing. If splicing is necessary for manufacturing, the shortest length of the spliced tube should not be less than 500mm, and the weld should be avoided as much as possible in the high temperature area of the furnace. 3.1.2.2 For each coil (snake) tube, one weld joint is allowed for every 4 meters of its total length. The length of the spliced tube is generally not less than 2.5 meters, and the shortest is not less than 500mm. 3.1.2.3 The splicing seam of the pipe should be located in the straight section of the pipe (except for coils). The distance from the center line of the weld to the starting point of the pipe bending or the edge of the bracket should be not less than 80mm. 3.1.3 Pipe bending
3.1.3.1 Stainless steel pipes should be cold bent, and carbon steel and alloy steel pipes can be hot bent or cold bent. 3.1.3.2 When bending the pipe by heating, the temperature should be raised slowly and evenly to ensure that the pipe is heated through and to prevent overburning and carburization. The heating method is determined by the manufacturer.
3.1.3.3 Regardless of whether the pipe is hot-bent or cold-bent, all bent parts are not allowed to have bulges, wrinkles, kinks and other defects that seriously affect the quality. If there are defects, grinding is allowed. The minimum wall thickness after grinding should not be less than 90% of the nominal wall thickness of the pipe and not less than the designed calculated wall thickness.
3.1.3.4 The minimum bending radius of the bent pipe shall comply with the provisions of Table 3.1.3-1. Minimum bending radius of bent pipe
Pipe category
Medium and low pressure steel pipe
High pressure steel pipe
Bending method
Hot pushing
Flaming bending or cold bending
Note: ①DN represents the nominal diameter of the pipe:
②D. represents the outer diameter of the pipe.
Minimum bending radius
3.1.3.5 The allowable deviation of the bending angle of medium and low pressure pipes shall comply with the following provisions: 70
Table 3.1.3-1
or D.
(1) The deviation of the bending angle of the elbow on the same plane shall not exceed ±1° (2) Deviation of the spatial angle α of two elbows not on the same plane: When the angle is 90°, the deviation shall not exceed ±1° (Figure 3.1.3-1). When the angle is greater than 90°, the deviation should not exceed ±1.5° (Figure 3.1.3-2) 90°±1
Figure 3.1.3-1 90° angle deviation
3. 1. 3. 6
Figure 3.1.3-2>90° angle deviation
High-pressure pipe bending angle deviation value Af shall not exceed ±1.5mm/m, and the maximum shall not exceed ±5mm (Figure 3.1.3~3).
Figure 3.1.3-3 Bending deviation
3.1.3.7 The surface angle △a of the pipe elbow shall not exceed the provisions of Table 3.1.3-2 (Figure 3.1.3-4). Figure 3.1.3-4
Flatness deviation
Length, mm
Flatness Aa, mmwww.bzxz.net
L≤500
Flatness of pipe elbow
500L≤1000
1000400mm, Aas(2) Pipe end length deviation A≤
(3) The offset AC of the outermost pipe section in the width direction should not be greater than 5mm. (4) The offset Ab of the elbow in the length direction should comply with Table 3.1.3-3. Elbow offset in length direction
Serpentine pipe length L, mm
Elbow deviation b≤, mm
L≤6000
6000L≤8000
Table 3.1.3-2
L>1500
Table 3.1.3-3
L>8000
(5) The offset Ae of adjacent elbows or any two layers of serpentine elbows in the length direction should not be greater than D./4 (D. is the outer diameter of the pipe), and not greater than 8mm.
3.1.3.9 The difference between the individual coils of the flat serpentine tube and the overall plane of the serpentine tube (Figure 3.1.3-6). After the tube clamp is installed, the flatness of the flat serpentine tube (Figure 3.1.3-7) AC value should not be greater than 6mm. 72
Figure 3.1.3-6 Serpentine tube plane difference
Figure 3.1.3-7 Serpentine tube flatness
The coil deviation should comply with the following provisions (Figure 3.1.3-8) 3.1.3.10
Coil deviation
Figure 3, 1.3-8
(1) Coil outer diameter deviation: AD ≤ ± 10mm. (2) Pipe spacing deviation: Ab ≤ ± 3mm.
3) Coil height deviation AH is allowed to be 3mm per meter, and the total length should not be greater than ± 6mm. (4) The deviation Af between the individual tube rings of the coil and the inner and outer surfaces of the coil shall not be greater than 5 mm. (5) The pipe end offset Aa and the pipe end length deviation N shall be in accordance with the provisions of 3.1.3.8 (1) and 3.1.3.8 (2). 3.1.3.11 The wall thickness reduction b at the pipe elbow shall be calculated according to formula 3.1.3-1, and its value shall not exceed: 10% for high-pressure pipes and 15% for medium- and low-pressure pipes, and the wall thickness shall not be less than the designed calculated wall thickness b
(3.1.3-1)
Where: b-the wall thickness reduction at the elbow, mm; ae-the actual wall thickness of the pipe, mms
Omin-the wall thickness at the thinnest part of the elbow cross section, mm. 3.1.3.12 The roundness a at the pipe elbow shall be calculated according to formula 3.1.3-2, and its value shall not exceed: 5% for high-pressure pipes and 8% for medium- and low-pressure pipes.
Where: a—roundness of the pipe at the elbow,
Dmx -Drl ×100%
Dmax—maximum outer diameter on the elbow cross section, mm; Dmin—minimum outer diameter on the elbow cross section, mm. (3.1.3-2)
3.1.3.13 For elbows with stress corrosion, stress relief heat treatment shall be performed regardless of the wall thickness. The heat treatment conditions of commonly used steel pipes after cold bending can be referred to Table 3.1.3-4. Heat treatment conditions after cold bending of pipes
12CrMo
15CrMo
12Cr1Moy
1Cr18Ni9Ti
Cr25Ni20
Cr16Ni36
INCOLOY8OOH
Heat treatment temperature
680~700
720~760
1100~1150
Insulation time
(m in/mm wall thickness)
2.4min/mm, but
not less than 1h
Heating rate
(℃/h)
Table 3.1.3-4
Cooling method
Furnace cooling to 300℃ and then air cooling
Furnace cooling to 300℃ and then air cooling
Water rapid cooling
Note: Cr25Ni20Cr16Ni36, INCOLOY800H, when the design temperature is lower than 816C, heat treatment is not required. Steel pipes should be heat treated as required after hot bending, and the heat treatment conditions shall be as specified in Table 3.1.3-5. 3.1.3.14
12CrMo
15CrMo
12Cr1Moy
1Cr18Ni9Ti
Cr25Ni20
Cr16Ni36
INCOLOY800H
Processing temperature (℃)
920~900
1020~980||t t||Heat treatment conditions after hot bending of pipes
Constant temperature time
2min per mm wall thickness,
but not less than 1/2h
1min per mm wall thickness, not
less than 20min
Add 760720 tempering
875-850
Complete annealing
750~725
High temperature tempering
1 100~1050
Constant temperature for 3h
Constant temperature for 2h
Constant temperature for 2.5h
2.4min per mm wall thickness,
but not less than 1h
Cooling method
Table 3.1.3-5
Cool in still air above 5℃
Lower to 600℃ at a rate of 15℃/h, and then cool in still air above 5℃||t t||Reduced to 600℃ at a speed of 40-50℃/h, and then cooled in still air above 5℃. The hardness after treatment is HB200~225
Quick cooling with water
3.1.4 Pipe and fittings assembly
3.1.4.1 When pipes and fittings with the same wall thickness are assembled, the inner walls should be flush, the inner wall misalignment 4 should not exceed 10% of the wall thickness, and the ear should not be larger than 1mm (Figure 3.1.4-1). Figure 3.1.4-1: Misalignment of inner wall
3.1.4.2 When pipes and fittings with different wall thicknesses are paired, if the misalignment of the inner wall exceeds 1mm, they should be processed according to the following specified types (Figure 3.1.4-2)
LrLz≥4(-82)
Figure 3.1.4-2 Inner wall bevel
Outer wall misalignment: When the thickness of the thin part is less than or equal to 10mm, the thickness difference is greater than 3mm; when the thickness of the thin part is greater than 10mm, the thickness difference is greater than 30% of the thin wall thickness, or exceeds 5mm, it should be processed according to the following types (Figure 3.1.4-3). NN
LL24(1-)
Figure 3.1.4-3 Outer wall bevel
3.1.4.3 When the difference between the inner and outer walls caused by the combination of pipes and fittings with the same nominal diameter but different actual outer diameters exceeds the provisions of 3.1.4.2, they should be machined in accordance with the provisions of this clause. The center and weld groove should be pushed as far as possible, and ab≤2mm (Figure 3.1.4-4).
Figure 3.1.4-4 Misalignment of the two pipe walls
3.1.4.4 The end face inclination deviation Af at the joint of pipes and fittings is 1% of the outer diameter of the pipe or fitting, but shall not exceed 2mm (Figure 3.1.4-5).
Figure 3.1.4-5 End face deviation
3.1.5 Fin tube manufacturing Except for high-frequency resistance welded spiral fin tubes in accordance with the national professional standard ZBG93010, if there is no regulation in the design, the following requirements shall be followed.
3.1.5.1 The root of the wound fin or sleeve fin must be close to the tube, and polygonal edges are not allowed. 3.1.5.2 The connection between the wound fin and the sleeve fin and the root of the tube shall be continuous welding, and arc welding, gas shielded welding, high-frequency resistance welding and brazing can be used for welding. 3.1.5.3 Fin welding rate: high-frequency resistance welded spiral fins should be no less than 90% (including alloy steel and stainless steel fins), and fins brazed and other welding methods should be no less than 95%. 3.1.6 Nail head pipe manufacturing
3.1.6.1 The nail head should be perpendicular to the pipe, and its inclination should not exceed 2mm. The distance error of the nail head along the circumference and longitudinal direction of the pipe should not exceed ±2mm.
3.1.6.2 More than 80% of the area at the bottom of the nail head should be fused with the pipe metal. 3.1.6.3 The total number of nail heads is allowed to have an error of ±2%. 3.1.6.4 The bending of the nail head pipe should not exceed 8mm along the entire length. 3.2 Centrifugal casting furnace pipe
3.2.1 General principles
3.2.1.1 The manufacture of harp pipe rows shall comply with the provisions of CHJB301. 3.2.1.2 The manufacture of non-harp pipe rows shall comply with the provisions of this technical condition. If the design has higher or special requirements, it should be stated in the drawings or relevant technical documents. 77
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