SY/T 4083-2024 Code for electric heat treatment of eliminating pipelinewelding residual stress English, Anglais, Englisch, Inglés, えいご
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ICS
E
Professional standard of the People's Republic of China
SY/T 4803-2024
Replaces SY/T 4803-2012
Evaluation Code for electric heat treatment of eliminating pipeline welding residual stress
油气管道电热法消除焊接残余应力热处理工艺规范
(English Translation)
Issue date: 2024-12-25 Implementation date: 2025-06-25
Issued by National Development and Reform Commission, P.R.C
Contents
1 General provisions
2 Terms
3 Equipment and insulation materials for heat treatment
3.1 General requirements
3.2 Electric heating system
3.3 Temperature control and measurement system
3.4 Insulation materials
4 Heat treatment process
4.1 General requirements
4.2 Heat treatment process specification
4.3 Heat treatment construction technique
4.4 Quality inspection of heat treatment
5 Heat treatment records
Appendix A Reports for pipeline welding joint heat treatment
Explanation of wording in this code
List of quoted standards
Addition: Explanation of provisions
1 General Provisions
1.0.1 This code is formulated to regulate the construction of heat treatment for eliminating welding residual stress in oil and gas field pipeline engineering using the electric heat method, and to ensure project quality.
1.0.2 This code applies to the heat treatment for eliminating residual stress in welded joints of carbon steel and non-heat-resistant low alloy steel pipelines.
1.0.3 In addition to complying with this code, the construction of heat treatment for eliminating welding residual stress in oil and gas pipelines using the electric heat method shall also comply with current relevant national standards.
2 Terms
2.0.1 electric heat method
A heating method using electrical energy as the heat source.
2.0.2 electric resistance heater
An electric heater using metal resistance wire/cable as the heating element and high-strength, good thermal radiation resistant material as insulation.
2.0.3 medium frequency induction heater
Equipment that uses the principle of medium frequency electromagnetic induction to generate eddy currents in the workpiece placed within the induction coil, thereby heating the workpiece to the required temperature.
3 Heat Treatment Equipment and Insulation Materials
3.1 General Provisions
3.1.1 The electric heating heat treatment equipment system shall include an electric heating system, a temperature control and measurement system.
3.1.2 The electric heating system shall include a heat treatment power supply and electric heaters.
3.1.3 The temperature control and measurement system shall include a control system, temperature measurement equipment, recording equipment, and auxiliary materials.
3.1.4 Heat treatment equipment shall have programmable intelligent temperature control functionality, and should have capabilities for data storage, real-time upload, and positioning.
3.1.5 Heat treatment equipment shall have a factory qualification certificate and instruction manual. Thermocouples and measuring instruments used during the heat treatment process shall be verified or calibrated and used within the validity period.
3.1.6 Insulation materials shall have quality certification documents and shall meet relevant health, safety, and environmental requirements.
3.2 Electric Heating System
3.2.1 The output power of electric heating equipment shall be adjustable, and the maximum power shall meet on-site usage requirements.
3.2.2 The structural type of electric resistance heaters should be rope-type or blanket-type, and the lead wires should be in the form of insulated plugs.
3.2.3 The structural type of medium frequency induction heaters should be winding-type or wrapping-type, shall be equipped with an output isolation transformer, and the protection level shall not be lower than IP23.
3.2.4 The power supply for heat treatment shall be 380V or 220V AC power.
3.2.5 The power supply shall be capable of continuous power supply, and the power supply capacity shall be greater than the electrical load required for heat treatment.
3.3 Temperature Control and Measurement System
3.3.1 The temperature control and measurement system shall have automatic temperature control functionality to achieve closed-loop control of the heat treatment temperature.
3.3.2 Temperature measurement shall use thermocouples. Thermocouples shall comply with the provisions of the current national standard "Thermocouples — Part 1: EMF specifications and tolerances" GB/T 16839.1.
3.3.3 Thermocouples should be fixed by spot welding, or by other methods that ensure tight contact between the thermocouple tip and the workpiece.
3.3.4 The diameter of spot-welded thermocouple wires should be 1 mm.
3.3.5 The temperature recorder shall have the capability for continuous recording, storage, and printing of heat treatment parameters.
3.3.6 The thermocouple index number shall match the control instrument and the recording instrument.
3.3.7 The cold end of the thermocouple shall be connected using compensation wires. Thermocouple compensation wires shall comply with the provisions of the current national standard "Compensating cables for thermocouples" GB/T 4989.
3.4 Insulation Materials
3.4.1 Aluminum silicate fiber wool should be selected as the insulation material. Its performance shall meet the requirements of the heat treatment process and environmental protection, and shall comply with the following provisions:
1 Temperature resistance: greater than or equal to 1000°C.
2 Thermal conductivity: the average test value at 600°C shall not exceed 0.14 W/(m•°C).
3 Shall not contain elements or impurities harmful to the pipeline.
3.4.2 The surface of the insulation material shall be covered, and the storage location shall have moisture-proof measures.
4 Heat Treatment Process
4.1 General Provisions
4.1.1 Heat treatment operators shall undergo professional training and pass assessments before starting work.
4.1.2 Before heat treatment construction, measures shall be taken to protect against wind, rain, and snow based on the site environmental conditions.
4.1.3 For pipeline welded joints with poor rigidity or those bearing heavy loads, anti-deformation measures shall be taken.
4.1.4 Valves, instruments, etc., adjacent to the pipeline welded joint being heat treated shall be effectively isolated or cooled.
4.1.5 The heat treatment equipment shall be grounded, with a grounding resistance not exceeding 4Ω. The pipeline being heat treated shall also be grounded, with a grounding resistance not exceeding 10Ω.
4.1.6 The appropriate heater shall be selected based on the pipeline specifications and the type of welded joint. The selection of electric heaters shall also comply with the following provisions:
1 When the nominal diameter of the pipeline welded joint is less than or equal to 100 mm, a rope-type electric heater should be selected; when the nominal diameter of the pipeline welded joint is greater than 100 mm, a blanket-type electric heater should be selected; for gathering pipelines with a nominal diameter greater than 300 mm, a medium frequency induction heater should be used.
2 When the minimum heating band widths of two adjacent welds overlap such that they can be heated using a single circuit heater (Figure 4.1.6), the respective insulation widths should not be less than the heating band width plus 200 mm.
4.2 Heat Treatment Procedure Specification
4.2.1 Before heat treatment construction, a heat treatment procedure specification shall be prepared. Heat treatment construction shall be carried out according to the provisions of the heat treatment procedure specification.
4.2.2 The preparation of the heat treatment procedure specification, in addition to complying with the provisions of this code, shall also comply with the engineering design documents, welding procedure qualification, and current relevant national standards. It shall be reviewed and approved before implementation. The heat treatment procedure specification shall at least include the following:
1 Material, specification, and type of the pipeline welded joint.
2 Model of the heat treatment equipment.
3 Type of heater and width of the heating zone.
4 Specifications and models of thermocouples and temperature recorder, number and location of temperature measurement points.
5 Material and specifications of insulation material, insulation thickness and width.
6 Heating rate and requirements.
7 Soaking temperature and time, allowable temperature deviation during soaking.
8 Cooling rate and requirements.
9 Quality inspection requirements after heat treatment.
4.3 Heat Treatment Construction Process
