GB/T9711-2011 L290N/X42N PSL2 LSAW pipeline adoption of high frequency welding process,L290N/X42N PSL2 LSAW pipeline is mainly used for structural scaffolding tube, low pressure liquid conveying, such as water, gas and oil, construction, such as architectural greenhouse,its surface can be coated with epoxy coating, coal tar epoxy resin, 3PE, extinction coating, asphalt coating, black oil coating According to customer requirements.