The article gives an overview of the properties and reliability of butadiene-acrylonitrile rubber sealant. The sealant has two parts, while the front edge has a special strengthening (reinforcement) that provides resistance while working under pressure. The back edge is more elastic, which is required to increase the tightness of the contact with the pipe wall. Both components are welded together, working as a whole part. It is a well-known fact that when the temperature goes up, the rubber strength goes down. Therefore, at a high temperature the sealant may disintegrate due to its reduced strength parameters. Since the sealant consists of two parts, a transition from a reinforced to the non-reinforced metal takes place in the working area. This transition becomes a tension concentrator, and locally, their levels may go well above the strength limit of the elastomeric sealant. This will lead to the subsequent disintegration of the sealant and peeling of the two edges from one another. The other aim of this article is to evaluate the reliability and critical parameters of the sealant at increasing temperatures and pressure changes to determine the possible safe operating conditions. The article presents laboratory research of the physical and mechanical properties of the elastomer before and after operation. Optimal work modes were identified. Their reliability parameters were evaluated in the course of operation based on the tension field calculations. Studies of increased temperature impact on the sealant strength were conducted. The aftereffects of the reinforcement grid displacement worth several millimeters against the computational position were measured. The finite elements method was used for the analysis.
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