Questions regarding the selection of pipeline materials for GC1 grade
Thread Content
Both TSG D0001-2009 and GB20801-2020 state that carbon structural steel cannot be used for GC1-grade pipes, but some people claim that 20G as specified in GB5310 can be used for such pipes; I’m quite confused ? According to the textbook \"Engineering Materials\", carbon steel is divided into carbon structural steel and carbon tool steel. Carbon structural steel is further classified into ordinary carbon structural steel (denoted by Q plus the yield strength value, such as Q245) and high-quality carbon structural steel (specified by the decimal fraction of carbon content, such as 20, 45, etc.). 20G belongs to high-quality carbon structural steel; according to TSG D0001 and GB20801, it should not be used in GC1-grade pipelines. Do these two regulations refer only to ordinary carbon structural steel? Is that not a precise enough expression?
I also want to ask: foreigners all use ASME carbon steel. . Why is Steel 20 permitted for use?
TSG technical specifications – these are departmental mandatory standards, and they take precedence over ** and industry standards. As an aside, TSG D0001 was updated to 2018
5310 is the manufacturing standard for seamless steel tubes used in steam boilers and pipelines operating at high pressures or above; it is also a recommended standard. There is no indication that it can be used for GC1 pipelines. Assuming that it may meet the requirements of such applications, or perhaps it can satisfy even more conditions, the fact remains that it cannot be used if it isn’t suitable. Experts will not ignore the standards and mandatory regulations just because certain requirements are met.