HG/T 2120-1991 Specification for single tube parallel flow internals of ammonia synthesis tower
Some standard content:
Chemical Industry Standard of the People's Republic of China
Technical Conditions for Single-tube Parallel-flow Internals of Ammonia Synthesis Tower Subject Content and Scope of Application
HG/T2120--91
1.1 This standard specifies the manufacturing, inspection and acceptance requirements for single-tube parallel-flow internals of ammonia synthesis tower. 1.2 This standard applies to DN600mm, DN800mm and DN1000mm internals of ammonia synthesis tower (hereinafter referred to as internals) with a design pressure not exceeding 1.8MPa and a design temperature not exceeding 550℃ 2 Reference Standards
Steel Pressure Vessels
GB1234
Steel Shell and Tube Heat Exchangers
High Resistance Electric Heating Alloys
GB1800~1804
Tolerances and Fits
GB2270
GB3003
GB3323
JB2536
JB4708
3 Technical requirements
Stainless steel seamless steel pipe
Ordinary aluminum silicate refractory fiber felt
Radiography and quality classification of steel fusion welding butt joints Pressure vessel painting, packaging, transportation
Welding process assessment of steel pressure vessels
Alkali-free glass fiber cloth
Asbestos cloth
3.1 Materials
3.1.1 The main material should be 0Cr18Ni11Ti, 0Cr19Ni9.1Cr18Ni9Ti can be used as a substitute material.
3.1.2 The material should comply with the relevant standards and relevant technical requirements, and should have a quality certificate from the material manufacturer, which should at least include the following: manufacturer name, steel grade, furnace (tank) number, batch number, measured chemical composition and mechanical properties, and heat treatment status of the supply. The manufacturer can conduct re-inspection. 3.1.3 Welding materials shall comply with relevant standards and can only be used after acceptance. 3.1.4 The outer diameter and wall thickness limit deviation of the heat exchange tube of the heat exchanger shall comply with the advanced precision of GB2270. 3.1.5 The electric furnace wire material shall comply with the provisions of GB1234. 3.1.6 The surface of the amber mica plate shall not be allowed to have cracks or delamination. 3.1.7 The alumina insulator of the electric heater is required to have an aluminum oxide (Al,O,) content of not less than 95%, and a high temperature withstand voltage test shall be performed. The test method and acceptance requirements shall be in accordance with the provisions of 4.4.1. 3.1.8 Shibai cloth, alkali-free glass fiber cloth and ordinary aluminum silicate refractory fiber felt shall comply with the provisions of JC210, JC170 and GB3003 respectively.
3.2 Manufacturing
Approved by the Ministry of Chemical Industry of the People's Republic of China on August 19, 19916
Implemented on January 1, 1992
HG/T2120-91
3.2.1 Welding
3.2.1.1 The welding of internal parts shall be performed by welders who have passed the welding test for similar materials. 3.2.1.2 The process qualification of internal welding shall be in accordance with the provisions of JB4708 and Appendix C of GB151. The requirements for weld repair and welder marking shall be in accordance with the provisions of GB150.
3.2.2 When hot working stainless steel parts, try to avoid long-term heating above 600℃, otherwise they should be solution treated. 3.2.3 The limit deviation of the un-toleranced dimensions of machined parts shall comply with the provisions of GB1804. The machined surface is IT14 and the non-machined surface is IT16.
3.2.4 Catalyst basket
3.2.4.1 The limit deviation, roundness and straightness tolerances of the catalyst basket body diameter shall comply with the provisions of Table 1. Table 1
Tower nominal diameter
DN1000
Diameter grade limit deviation
Straightness tolerance
Straightness tolerance
Length limit deviation
Conforms to GB1800~1804
shall not exceed
1/1000 of the cylinder length, shall not be
greater than 4
IT14 grade within the full length range, and
within the full length range is ±5
3.2.4.2 The center tube should be made of a whole seamless steel pipe, and its straightness shall not be greater than 1mm within any 2m length range, and the straightness of the total length shall not be greater than 3mm. When two pipes are spliced, the short pipe length shall not be less than 500mm, and the weld structure shall be of the insert type. 3.2.4.3 The cold pipe must be straightened before bending and before the thermocouple sleeve is assembled: its straightness tolerance shall not exceed 1-mm within the 2m length range, and the straightness of the total length shall not exceed 3mm. 3.2.4.4 The cold pipe should be made of a whole seamless steel pipe. When two pipes are spliced, the short pipe length shall not be less than 500mm. 3.2.4.5 The cold pipe with an intermediate fan structure shall not have cracks and unevenness after manufacturing. The flattened pipe shall not be spliced. 3.2.4.6 The thermocouple sleeve should be made of a whole seamless steel pipe. It is allowed to connect two pipes, but the connection shall not fall on the elbow. The length of the short pipe during splicing shall not be less than 2m. 3.2.5 Heat exchanger 3.2.5.1 The diameter limit deviation, state and straightness tolerance of the heat exchanger cylinder shall comply with the provisions of Table 2. Table 2 Diameter limit deviation The straightness tolerance of the cylinder shall not exceed 1/1000 of the cylinder length. 3.2.5.2 The heat exchange tube shall be manufactured as a whole seamless steel pipe and shall not be spliced. The appearance inspection and straightening shall be carried out one by one. 3.2.5.3 The diameter and deviation of the tube holes on the tube sheet and baffle shall comply with the provisions of Table 3. The outer diameter of the arm and the hole diameter shall comply with the requirements of Table 4. Hole diameter
Outer diameter of pipe
Distance between center of hole
Maximum hole
Nominal hole bridge
Limit deviation
Adjacent holes of baffle
Distance between center of hole
Allowable hole bridge width B (96% of the hole bridge
width must be equal to or greater than the following value) Tube sheet thickness
Limit deviation
Minimum hole bridge
Tube extension length: 1.0~1.5mm for manual arc welding, 3.2.5.4 The connection between pipe and tube sheet is welding, and 0.5~1.0mm for argon welding. After the pipe and tube sheet are welded, the parallelism tolerance of the two tube sheets shall not exceed 2mm. 3.2.5.5 The nitrogen synthesis tower of byproduct steam and the gas distribution box of the heat exchanger must be thoroughly cleaned before assembly and welding. There must be no iron filings, burrs, dirt and rust.
3.2.6 Electric heater
3.2.6.1 The electric furnace wire should be manufactured in one piece. 3.2.6.2 The electric furnace wire should be straightened and not twisted. 3.2.7 Thermocouple tube
3.2.7.1 Thermocouple tube must be straightened before assembly. Its straightness tolerance is not more than 1mm within any 2m length, and the straightness tolerance of the total length is not more than 2mm
3.2.7.2 Thermocouple tubes are allowed to be spliced. The shortest length of the spliced tube shall not be less than 2m. 3.2.8 Insulation layer bZxz.net
3.2.8.1 Asbestos cloth should be baked dry before wrapping. 3.2.8.2 The overflow insulation material should be wrapped densely and evenly, and the outer diameter of the insulation sleeve should not exceed the size specified in the drawing. 3.2.8.3 The overflow insulation layer should be wrapped after the water pressure test. It should not be damp during the wrapping process, otherwise it should be dried again. 3.3 The straightness tolerance of the internal parts assembled as a whole shall not exceed 1/1000 of the total length and shall not exceed 6mm. The limit deviation of the total length is:
DN1000 tower, ±12mm;
DN800 tower, ±10mm;
DN600 tower, ±8mm.
4 Test methods and inspection rules
4.1 Acceptance of all parts and finished products a. Inspection of material quality certification documents;
HG/T2120
b. Appearance inspection (including appearance inspection of welds) c. Dimension inspection.
4.2 Catalyst basket
4.2.1 The straightness tolerance of the cylinder is checked by pulling a 0.5mm thin steel wire at the intersection of the horizontal and vertical planes of the cylinder axis and the cylinder, that is, at four locations along the circumference of 0°90°, 180°, and 270°. The distance between the measuring position and the longitudinal weld should not be less than 100mm.
4.2.2 All welds should be visually inspected, and the length of the radiographic flaw detection of each butt weld of the cylinder should not be less than 20%. For the inner and outer surfaces of the welds of the catalyst basket cylinder of DN800mm and DN1000mm towers and the outer surface of the welds of the DN600mm cylinder, a 100% coloring test should be carried out, and then a water pressure test should be performed.
4..3 For the weld of the catalyst basket cylinder, one welding test plate shall be made for each unit, and the made test specimens shall meet the following requirements: a.
2 tensile test specimens;
2 bending test specimens;
2 gold test specimens of the welded joint (one each for low-magnification organization and microstructure). c.
4.2.4 The butt welds of cold pipes shall be subjected to 100% radiographic inspection and color inspection. After welding, a ball with a diameter of 0.85 times the inner diameter of the pipe shall be used for ball inspection, and each pipe shall be subjected to a water pressure test. The test pressure shall be twice the design pressure, and the pressure shall be maintained for 5 minutes. 4.2.5 For cold pipes with intermediate flattening structures, the flattened parts shall be subjected to 100% color inspection. 4.2.6 Cold pipes and annular pipes shall be subjected to ball inspection with the balls specified in Table 5. 100% color inspection is carried out on the bending part, table s
bending radius R
pipe outer diameter d
ball diameter d
pipe inner diameter d,
4.2.7 The cold pipe and the ring pipe shall be welded circle by circle and color inspection shall be carried out. There shall be no defects such as cracks, pores, arc pits, slag inclusions and undercuts. 4.2.8 The butt welds of thermocouple tubes and thermocouple sleeves shall be subjected to 100% radiographic inspection and color inspection. After welding, a ball with a diameter of 0.9 times the inner diameter of the tube shall be used for ball inspection, and each tube shall be subjected to a water pressure test. The test pressure is: 2 times the design K force for thermocouple sleeves, and the pressure is maintained for 5 minutes; 1.25P for thermocouple tubes,
MPa, and the pressure is maintained for Smin.
Note: P,—the design K force of the nitrogen synthesis tower shell, MPa; (8)—the allowable stress of the material at the test temperature. MPa (8—Material stress at design temperature. MPa.4.2.9 After the cold tube bundle is assembled, a gas test shall be carried out. The test pressure is 1.15P as specified in GB150. The central tube butt weld shall be inspected by 100% radiographic inspection and can pass through the porous plate smoothly. The MPa gas pressure test method shall be in accordance with the MPa gas pressure test method. 4.2.11 The catalyst basket cylinder shall be subjected to a water pressure test of 1.25P. 4.3 Heat exchanger HG/T2120-91 MPa for 30min. 4.3.1 The heat exchange tubes shall be subjected to a water pressure test phase by phase. The test pressure is twice the design pressure. The pressure is maintained for 5s. 4.3.2 After the heat exchanger is assembled and welded, a water pressure test shall be carried out with a force of 1.25PMPa for 30min. , the upper and lower heat exchangers of the by-product steam ammonia synthesis tower internals should be subjected to water tests separately. 4.4 Electric heater
4.4.1 In each batch of sintered finished products of alumina insulation, 10% (not less than 2 pieces) of each type are selected as heat-resistant samples. The test is to send the sample into the heating furnace, heat it to 1400℃ at a rate of 200℃ per hour, keep it warm for 1h, cool it at room temperature after taking it out, and then send it into the furnace to heat it again. After heating and cooling three times, if there are no cracks on the surface, the batch of finished products is considered qualified. The withstand voltage should be 1000V at 1000℃
4.4.2 After assembly, the electric heater should be inspected and the insulation resistance should be measured. The corresponding records should be made when the insulation resistance is greater than 2M2. 4.5 The chloride ion content of water used for water pressure test shall not exceed 25ppm. 4.6 All All parts that pass the water pressure test need to be blown dry with compressed air on the inner and outer surfaces. 4.7 Radiographic inspection shall be in accordance with the provisions of GB3323, and level II is qualified. Color inspection shall be in accordance with the provisions of Appendix H in GB150. 5 Technical documents
Factory certificate;
Quality certificate (chemical composition, mechanical properties, non-destructive testing, welding quality, water pressure test, etc. of the main parts and components h.
Items;
Product manual (installation manual, operating manual and product completion drawing). c
Note: 1) The main parts include center tube, catalyst basket body, half cover, tightening ring, cold tube, thermocouple tube, thermocouple sleeve, heat exchanger body, tube sheet, column arm, dimensional body, electric heater
6 Marking, packaging, transportation, storage
6.1 Marking
After the catalyst basket and heat exchanger are packed, the manufacturer shall determine the center of gravity and make marks. 6.2 Packaging and transportation
6.2.1 The internal parts of the ammonia synthesis tower shall not be painted. Protective measures shall be taken for the threads and joint surfaces. The spherical surface of the support tubes at both ends of the heat exchanger shall be coated with anti-rust grease.
6.2.2 The catalyst basket, heat exchanger, electric heater and thermocouple of the hydrogen synthesis tower internal parts should be packed separately before leaving the factory. When the internal parts are packed as a whole before leaving the factory, measures should be taken to prevent the deformation and damage of the parts. 6.2.3 The delivery list and technical documents shall be delivered together with the equipment. The delivery list shall include the name of the manufacturer, product number, etc. 6.2.4 When packing the upper and lower sections of the internal parts of the ammonia synthesis tower for by-product steam, the heat exchanger and the bottom extension tube shall be firmly wrapped. 6.2.5 The parts and cylinders in the catalyst basket shall be fixed with this support. 6.2.6 Other technical requirements shall comply with the relevant provisions of JB2536. 6.3 Storage
When the internal parts are stored in the open air, measures shall be taken to prevent rain, moisture and sunlight. 10
Additional instructions:
HG/T212091
This standard is proposed by China Chemical Equipment General Office. This standard is under the jurisdiction of the Chemical Industry Ministry's Chemical Machinery Equipment Standardization Technical Unit (Chemical Industry Ministry's Chemical Machinery Research Institute). This standard is drafted by Nanjing Chemical Industry Company Chemical Machinery Factory, and the drafter of this standard is Luo Hongjuan.
This standard is entrusted to the Chemical Industry Ministry's Chemical Machinery Equipment Standardization Technical Unit for interpretation.2 Packaging and transportation
6.2.1 The internal parts of the ammonia synthesis tower shall not be painted. Protective measures shall be taken for the threads and joint surfaces. Anti-rust grease shall be applied to the spherical surface of the support tubes at both ends of the heat exchanger.
6.2.2 The catalyst basket, heat exchanger, electric heater and thermocouple of the hydrogen synthesis tower internal parts should be packaged separately before leaving the factory. When the internal parts are packaged as a whole before leaving the factory, measures shall be taken to prevent the deformation and damage of the parts. 6.2.3 The delivery list and technical documents shall be delivered together with the equipment. The delivery list shall include the name of the manufacturer, product number, etc. 6.2.4 When packaging the upper and lower heat exchangers of the by-product steam ammonia synthesis tower internal parts, the heat exchanger and the bottom protruding tube shall be firmly wrapped. 6.2.5 The parts and cylinder in the catalyst basket shall be fixed with this support. 6.2.6 Other technical requirements shall comply with the relevant provisions of JB2536. 6.3 Storage
When the internal parts are stored in the open air, measures should be taken to prevent rain, moisture and sunlight. 10
Additional instructions:
HG/T212091
This standard is proposed by China Chemical Equipment General Office. This standard is under the jurisdiction of the Chemical Industry Ministry's Chemical Machinery Equipment Standardization Technical Unit (Chemical Industry Ministry's Chemical Machinery Research Institute). This standard is drafted by Nanjing Chemical Industry Company Chemical Machinery Factory, and the drafter of this standard is Luo Hongjuan.
This standard is entrusted to the Chemical Industry Ministry's Chemical Machinery Equipment Standardization Technical Unit for interpretation.2 Packaging and transportation
6.2.1 The internal parts of the ammonia synthesis tower shall not be painted. Protective measures shall be taken for the threads and joint surfaces. Anti-rust grease shall be applied to the spherical surface of the support tubes at both ends of the heat exchanger.
6.2.2 The catalyst basket, heat exchanger, electric heater and thermocouple of the hydrogen synthesis tower internal parts should be packaged separately before leaving the factory. When the internal parts are packaged as a whole before leaving the factory, measures shall be taken to prevent the deformation and damage of the parts. 6.2.3 The delivery list and technical documents shall be delivered together with the equipment. The delivery list shall include the name of the manufacturer, product number, etc. 6.2.4 When packaging the upper and lower heat exchangers of the by-product steam ammonia synthesis tower internal parts, the heat exchanger and the bottom protruding tube shall be firmly wrapped. 6.2.5 The parts and cylinder in the catalyst basket shall be fixed with this support. 6.2.6 Other technical requirements shall comply with the relevant provisions of JB2536. 6.3 Storage
When the internal parts are stored in the open air, measures should be taken to prevent rain, moisture and sunlight. 10
Additional instructions:
HG/T212091
This standard is proposed by China Chemical Equipment General Office. This standard is under the jurisdiction of the Chemical Industry Ministry's Chemical Machinery Equipment Standardization Technical Unit (Chemical Industry Ministry's Chemical Machinery Research Institute). This standard is drafted by Nanjing Chemical Industry Company Chemical Machinery Factory, and the drafter of this standard is Luo Hongjuan.
This standard is entrusted to the Chemical Industry Ministry's Chemical Machinery Equipment Standardization Technical Unit for interpretation.
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