B/T9711-2011 PSL1 standard specifies the manufacturing requirements for seamless steel tubes and welded steel pipes for products for pipeline systems for the oil and gas industry.GB/T9711-2011 PSL1 standard is applicable to seamless steel tubes and welded steel pipes for oil and gas transportation.GB/T9711-2011 PSL1 standard does not apply to cast iron pipes.GB/T9711-2011 PSL1 L485,L450,L415,L390,L360,L320 and so on.