ENSURING THE STRENTH OF T-JOINT. STRENGTHENED CONNECTION PIPE

Abstract

Reliability of the entire system is determined by the reliability of its individual components. So, in pipeline transport, as in any system, it is possible to isolate some problematic ele-ments (sections) characterized by high accident rates. These, of course, include shaped products, in particular, T-joints. Thus, it is extremely important to pay special attention to the issues of improving the design of the connecting parts and the technologies for their installation during the construction and repair of pipelines. The purpose of this article is to present the design of a stabilizing device, namely a strength-ened branch pipe, installed as an intermediate part-insertion in place of the tapping hole into the pipeline. Similar in purpose to the products encountered in practice, there is a certain drawback, which is determined by the structural features of the strengthened pipes. Often at the stage of assembling the joint, it becomes necessary to cut the hole in the main line with a diameter much larger than the inside diameter of the pipeline tap, which in turn adversely affects the strength of the entire joint. The article presents the results of the strength analysis of tee connections made in three different designs: in the classical with the use of a T-type TS (tee-stamped) and on the basis of intermediate reinforcement inserts (reinforced butt joint and reinforced connection pipe). In the course of the research it was established that the design of the strengthened connec-tion pipe allows to reduce the peak values of equivalent stresses in the dangerous zone of the T-joints in comparison with the TS-type tees and the nodes strengthened by the branch pipe by 40-45 % and 15-20 % respectively. Also recommendations are given on the choice of strength characteristics and geometric parameters of the proposed connecting part in determining the bearing capacity of the pipeline.