Special air sealing threaded connector structure for casing pipe

The invention provides a special air sealing threaded connector structure for a casing pipe. The special air sealing threaded connector structure comprises a male end and a female end. Namely, a coupling is of a symmetrical structure. The casing pipe is arranged at the male end, and the male end is composed of a male thread with tapers, a male sealing surface and a shoulder, wherein the male sealing surface is arranged on the end portion of the male thread and the shoulder is arranged at the peak of the male sealing surface. The female end is composed of a female thread with tapers, a female sealing surface and a shoulder, wherein the female sealing surface is arranged on the end portion of the female thread and the shoulder is arranged at the rear of the female sealing surface. The male thread and the female thread are mutually twisted together, and the male sealing surface makes contact with the female sealing surface. The length of the center hole of the coupling meets the relational expression of Ld) 2Lp, wherein Lp= Ls * (sin15 degrees+cos15 degrees). The special air sealing threaded connector structure has the advantages that by the adoption of the connector structure, under the condition that the performance of connectors is guaranteed, the minimum length of the center hole is accurately determined, the influence area of the center hole is prevented from being interfered after the connectors at the two ends are buckled, materials of the coupling are saved, production cost is reduced, the range of the length of the center hole is determined, and the threaded connector structure can be applied to the casing pipe in a threaded connection mode of a threaded type or a sealing surface type or other types .