TaijiBlue^® PVC-O pipes seal ring and fittings are made according to China standards.

Seal rings standard: GB/T 21873-2008 Rubber seals—Joint rings for water supply, drainage and sewerage pipelines—Specification for materials
   

Ductile iron fittings standard: GB/T 13295-2013 Ductile iron pipes, fittings and accessories for water or gas applications.