Factory supplied threaded socket stainless steel couplings The casing is threaded to shorten the running time. The casing is a disposable material. Once problems occur in use, it will cause great losses, so the quality requirements for the casing are extremely strict. The special products of casing include special button type casing and casing with special materials and properties such as sulfur resistance, corrosion resistance and collapse resistance. Special button casing is mainly used for deep well cementing where the tensile strength of ordinary casing does not meet the requirements, and generally only one section is used at the wellhead; Sulfur resistant and corrosion-resistant casing is mainly used in deep and ultra deep wells of sour oil fields; Destructive casing is mainly used in deep wells and ultra deep wells in oil fields due to its high collapse pressure and good mechanical and collapse properties. Couplings are used to connect two joints of tubing coupling or…