لوله های بویلر فولادی بدون درز ASME SA213 T91
A213 T91 Alloy Pipe. A-213 T91: "A" is the mark of ASTM steel material. "213" refers to the specification reference number, "T91" refers to the steel grade classification, "T" refers to small diameter pipe, equivalent to China's 10Cr9Mo1VNbN pipe