LNG gas stations contain hydrogen sulfide; the pipes are made of 316L stainless steel. Can bolts be made of 304 (B8)?
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As the title suggests, I would like to ask the experts: for LNG gas stations where the wellheads contain hydrogen sulfide, should sulfur-resistant pipes made of 20G material be used? Is it acceptable to use 35CRMo according to the standards? Additionally, for the acid gas removal unit, the pipes are made of 316L stainless steel; can the flange bolts be made of 304 (B8)? Should we still use B8M bolts? Thank you
In environments containing hydrogen sulfide, it is appropriate to use 316L stainless steel pipes, as 316L has good corrosion resistance. However, for flange bolts, using 304 (B8) material may not be ideal. Due to its weak resistance to hydrogen sulfide, 304 stainless steel is prone to stress corrosion cracking. It is recommended to use B8M bolts, as they are made of 316 stainless steel, which provides better corrosion resistance compared to 316L pipes, and offers greater resistance to corrosion in environments containing hydrogen sulfide. .
LNG gas station; wellheads contain hydrogen sulfide; sulfur-resistant pipes made of 20G material; 35CRMO can be used in accordance with standards. That is what is referred to as B7 in American standards; however, B7M should be used in the presence of hydrogen sulfide, as B7M was developed specifically for environments with hydrogen sulfide. Specifically, one can refer to NACE and SH industry standards to check the materials for pipes and fasteners (depending on the specific processing requirements).