The base pipes of large-diameter water supply coated plastic steel pipes mainly include spiral seam welded steel pipes, straight seam submerged arc welded steel pipes, and straight seam high-frequency welded steel pipes. When the base pipe of large-diameter water supply coated plastic steel pipe is a spiral seam welded steel pipe, the technical requirements should comply with the provisions of SY/T5037-2018 standard for submerged arc welding of ordinary fluid transmission pipelines, GB/T9711-2017 standard for pipeline steel pipes for industrial pipelines, or GB/T3091-2015 standard for welded s