SY/T 4076-2016 "Technical Specification for Steel Pipeline Liquid Coating Air-sent Extrusion Coating Internal Coating" aims to ensure the construction mass of steel pipeline liquid Coating Air-sent Extrusion Coating Internal Coating and prolong the service life of the pipeline. This standard applies to steel pipelines for conveying crude oil, natural gas or water. The nominal diameter of the pipeline is DN50~ DN800, and the medium temperature is not higher than 80 ° C. The specification covers the construction and acceptance process, including the definitions and requirements of terms and methods such as mechanical cleaning and chemical cleaning. The inner coating should be designed according to the corrosion evaluation of the medium and the conditions of use of the pipe. At least two inner coatings should be applied. The specific grade and thickness shall comply with the provisions of the table 3.0.2 in the standard.