Development status and existing problems of standards for bimetal composite pipe

Regarding the deficiencies in the research of bimetal composite pipe products and related inspection and test standards, the development history of related standards for bimetal composite pipes at home and abroad as well as the establishment and revision of the current standards was introduced, and the main clauses of the standards for bimetal composite pipes at home and abroad were compared and analyzed. The results show that the current foreign standards for bimetal composite pipes are mainly Specification for CRA clad or lined steel pipe(API SPEC 5LD) series standards, which have been revised for 4 times. In China, based on API SPEC 5LD, the standard for bimetal composite pipes has been upgraded to Specification for CRA clad or lined steel pipe(SY/T 6623-2018)(3rd edition) by means of equivalent adoption and modified adoption. No matter at home or abroad, there are still problems in the standards of bimetal composite pipe, such as unclear specifications on collapse test, tightness test and bending test indexes of lined pipes, and the unspecified procedure qualification items for factories or construction welding of clad and lined pipes. In the future, the standards for bimetal composite pipes still need to be improved in combination with technical requirements such as manufacturing, inspection and engineering application.