Recently, the State Administration for Market Regulation and the Standardization Administration of China jointly released the national standard GB/T 26500—2025 Plastic-Lined Composite Steel Pipes and Fittings—Structural Types, Main Dimensions, and Basic Parameters. The new standard, which will replace the 2011 edition, is scheduled to take effect on March 1, 2026. As a core industry standard under the National Technical Committee for Standardization of Nonmetallic Chemical Equipment, it was revised under the leadership of Naifulong Group Co., Ltd., together with several key enterprises in the industry. Its release marks a new stage of high-quality development in China’s standardization of plastic-lined pipes and fittings.
Technology-Driven Progress, Standards First: Strengthening the Industry with Professional Expertise
As a leading domestic enterprise in the R&D and manufacturing of PTFE-lined valves and piping equipment, Naifulong Group played a central role throughout the entire revision process. In July 2024, during a standard revision workshop in Wenzhou, General Manager Fang Xianle and Executive Vice President Mou Xianzhong led the company’s core technical team in in-depth discussions with industry experts. Key topics included the unification of dimensions for the N series (domestic and joint-venture enterprises) and W series (export and foreign-invested enterprises), as well as flange optimization. These discussions laid a solid foundation for the scientific rigor, accuracy, and practicality of the new standard.
The release of this updated standard reflects not only the industry’s technological progress, but also Naifulong Group’s ongoing commitment to its mission of “dedication to corrosion resistance and continuous innovation.” Over the years, the company has consistently leveraged standards to drive technological advances and fueled industrial upgrading through innovation, continuously contributing strong momentum to the industry’s high-quality development.
Working Together for the Future: Advancing the Industry Toward Higher Quality

The implementation of GB/T 26500—2025 will further China’s standardization system for nonmetallic chemical equipment, significantly enhancing product consistency, operational safety, and international competitiveness across the industry. Looking ahead, Naifulong Group will continue to uphold its vision of “building industry benchmarks and promoting industrial development,” working with partners across the sector to drive the plastic-lined piping technology toward high-quality and sustainable growth, and to contribute core strength to the transformation and upgrading of China’s chemical equipment industry.

Company Profile
Naifulong Group Co., Ltd. is a leading domestic enterprise specializing in the R&D, production, and sales of PTFE-lined valves and piping equipment. With years of expertise in corrosion-resistant equipment, strong technical capabilities, and rigorous quality control, the company has become a key participant in industry standard formulation. It provides high-quality corrosion-resistant solutions for global chemical, pharmaceutical, and environmental protection industries.