Welding procedure qualification for petrochemical engineering
1 General provisions
1.0.1 This standard is formulated with a view to unifying the methods and contents of welding procedure qualification for petrochemical engineering, formulating the correct welding procedure and ensuring the engineering welding quality.
1.0.2 This standard is applicable to the welding procedure qualification for welding processes such as gas welding, manual arc welding, argon tungsten-arc welding, gas metal arc welding and submerged arc welding during the construction of atmospheric vessels, pressure vessels, industrial pipelines and special steel structures for petrochemical industry.
Notes:
① Industrial pipelines include process pipelines, utility pipelines and industrial furnace tubes.
② Special steel structure refers to that specified in SHJ 507-87 Code for construction and acceptance of special steel structures for petrochemical industry.
1.0.3 In addition to this standard, the welding procedure qualification for pressure vessels shall also comply with the design documents and the current relevant standard Welding procedure qualification for pressure vessels.
1.0.4 The welding procedure qualification for titanium materials shall be carried out according to the requirements of company standard SHJ 502-86 Code for construction and acceptance of titanium piping.
1.0.5 If welding procedure qualification is required for imported engineering items, but no specific requirements are proposed by the seller, this standard shall apply.
1.0.6 For the welding procedure qualification for atmospheric vessels, industrial pipelines and special steel structures, the welding procedure qualification reports that have passed the evaluation according to this standard may be used as the basis for compiling the welding procedure instructions among the organizations that have obtained the Manufacturing License for Pressure Vessels, provided that the approval by the technical chief of the construction organization is obtained in advance.
2 Basic provisions
2.0.1 The parent metal used for welding procedure qualification shall meet the requirements of design documents and relevant standards, and shall be provided with the factory quality certificate or re-inspection certificate.
When impact toughness is required in the design, the parent metal shall be provided with the qualification certificate or re-inspection certificate of impact toughness.
2.0.2 Electrodes, welding wires and fluxes shall be provided with factory quality certificates, and welding gas shall meet the requirements of relevant standards.
2.0.3 When the materials not listed in Table 3.1.3 hereof are used according to design, the welding procedure qualification shall be conducted after the confirmation for crack resistance of materials. The crack resistance of materials shall be confirmed through test. Carbon equivalent method and crack sensitivity coefficient method may be used as auxiliary methods (see Annex I).
When the materials listed in Table 3.1.3 are used according to design, if such materials have a large crack sensitivity and structural rigidity, it is necessary to determine whether to conduct crack resistance test by auxiliary methods.
2.0.4 The form and size of groove in welded joint shall meet the design requirements and the requirements of relevant codes. Unless otherwise specified, it shall be implemented according to the requirements of GB 985-80 Basic forms and sizes of weld grooves for manual arc welding, GB 986-80 Basic forms and sizes of weld grooves for submerged-arc welding and Table 2.0.4 "Forms and sizes of grooves in in welded joint of clad steel plate".
2.0.5 See Figure 2.0.5 for the classification of welding positions of test pieces under welding procedure qualification.
2.0.6 The welding equipment used in procedure qualification shall be in good condition; the mechanical testing machines and measuring tools can only be used after they have passed the appraisal by the metrological department.
Table 2.0.4 Forms and sizes of grooves in welded joint of clad steel plate
1 General provisions
2 Basic provisions
3 Principles of welding procedure qualification
4 Inspection and qualification of test pieces
Annex I Common methods for confirming crack resistance
Annex II Format of welding procedure qualification data
Annex III Explanation of wording
