城镇燃气钢质管道带压焊接工艺研究

阐述城镇燃气钢质管道带压焊接的意义,分析带压焊接工艺中避免产生氢致裂纹的条件。按照相关标准的要求,确定带压焊接适用范围。采用管材为Q235B,规格为D426 mm×7 mm的管件制成试验装置,以水代替天然气,模拟燃气管道实际运行条件,进行带压焊接试验,对试样进行检验。结果表明,在运行压力不大于0. 4 MPa,规格为D426 mm×7 mm的燃气钢质管道上实施焊接,可以避免产生氢致裂纹,同时对实施带压焊接工艺提出了合理化建议。

Research on in-service welding technology for steel gas pipeline

The significance of welding in service for steel pipelines of city gas was described and the conditions for avoiding hydrogen induced cracking in the process of welding in service was analyzed. According to the requirements of relevant standards, the applicable scope of welding in service was determined. A test device was made with pipe material of Q235B and D426 mm × 7 mm pipe fittings. Water was used to replace the natural gas when the actual operating conditions of the gas pipeline were simulated. The test of welding in service was carried out and the sample was inspected after welding. It was concluded that the welding of the gas steel pipe with the running pressure not more than 0.4 MPa and the specification of D426 mm × 7 mm can avoid hydrogen induced cracking. In addition, reasonable suggestions for implementing the pressure welding process were proposed.