Stainless steel 310S is an austenitic heat resistant alloy with excellent resistance to oxidation under mildly cyclicconditionsthrough 2000°F. Grade 310S is a lower carbon version, less prone to embrittlement and sensitisation in service. The highchromium and medium nickel content make these steels capable for applications in reducing sulphur atmospheres containing H2S.They are widely used in moderately carburising atmospheres, as encountered in petrochemical environments. For more severe carburising atmospheres other heat resisting alloys should be selected. Grade 310 is not recommended for frequent liquid quenching as it suffers from thermal shock. The grade is often used in cryogenic applications, due to its toughness and low magnetic permeability.The Olet is a reinforced pipe fitting used for branch pipe connection, which has been widely used abroad in recent years. It replaces the traditional branch pipe connection types such as reducing tees, reinforcement plates, and reinforced pipe sections. It has outstanding advantages such as safety and reliability, reduced cost, simple construction, improved medium flow channel, series standardization, and convenient design and selection. It is increasingly widely used in high-pressure, high-temperature, large-diameter, and thick-walled pipelines, replacing the traditional branch pipe connection method.