根据API规格5CT1988,有10种类型的套管钢等级,包括H-40,J-55,K-55,N-80,C-75,C-75,L-80,C-90,C-90,C-95,P-110, and Q-125.Casing shall be supplied with threads and couplings, or in one of the following pipe end forms: flat end, round thread with or without couplings, partial trapezoid thread with or without couplings, straight thread, special end work, sealing ring construction.According to SY/T6194-96, domestic casing should be tied with steel wire or steel belt.The exposed part of each sleeve and coupling thread shall be screwed with a guard ring to protect the thread. Specification range: OD: 114.3mm-508mm […]