CGA C-27-2019提供了一个标准程序，用于降低美国DOT 3系列无缝钢管的工作压力，这些钢管的局部薄区域不符合某些DOT规范的最小壁厚。该过程应由DOT认证的设施执行。本出版物不适用于因任何再鉴定方法而被定罪的管道。

CGA C-27-2019 provides a standard procedure to derate the service pressure of U.S. DOT 3-series seamless steel tubes with local thin areas that do not meet the minimum wall thickness of certain DOT specifications. This process shall be performed by a DOT qualified facility.This publication does not apply to tubes that have been condemned from any requalification method.