ISO 15741:2016 specifies the requirements and test methods for friction reduction coatings inside steel pipes and their fittings for non-corrosive gas delivery. The standard aims to reduce friction when gas flows and provide adequate corrosion protection. Coatings are usually applied with liquid epoxy coatings, which are applied to the inner walls of sand blasting clean steel pipes by techniques such as airless spray to ensure the smoothness and effectiveness of the coating. The standard specifies the application methods, requirements and test procedures for coatings, including coating thickness, liquid resistance and adhesion. This standard provides clear technical guidance for coating material manufacturers, construction companies and mass inspectors to ensure high performance and long-term durability of coatings.