This is a huge topic and worthy of discussion by many different types of professionals. In order to understand this discussion, one must understand that certified power plant materials cannot be free-traded like Wal-Mart toys. The purchaser cannot tell if a material is acceptable simply by looking at it. It must be certified.... the purchaser cannot tell if , for example, a heat treatment was done properly by inspection If a power plant is built in the USA to US standards, pressure retaining materials will be certified to ASME or ASTM material standards. If a supplier provides substandard materials and there is an accident, there is a LEGAL REMEDY to protect the purchaser. That legal remedy is a lawsuit..... However, the force of tort law does not extend to China. If you buy substandard materials from an international broker and it is "stamped" ASME XXXXX you have no means to proect yourself should the material fail in service. The stamping means nothing without the force of tort law. Now I am aware that a big AE firm can purchase insurance and indemnities to protect themeselves in just such a case.... But you should beware...... For powerplant materials, i am assuming that you are talking about important, expensive chrome-moly materilas such as P22/T22 and P91/T91. Read page #2 of this link.. http://absa.ca/newsletter/v06-2001/v6-iss3.pdf#search=""chinese%20flanges"" also, this link.. http://cisgw3.law.pace.edu/cases/990330c2.html and this one... http://www.eng-tips.com/viewthread.cfm?qid=116552&page=10 and , of course, the saga of Zidell Valve in the Chinese courts.. http://www.carnegieendowment.org/pdf/2005-04-18/lubman_pub1.pdf#search=""chinese%20flanges"" I would like to hear from others about thier experiences. -MJC