A safety device with a sliding cable and a corresponding installation, to secure conduits, pipes, piping and similar equipments subject to high pressure due to fluid under pressure circulating in such conduits and equipments. The safety device includes a flexible cable which forms a first and a second attachment eyelet for attaching and connecting the safety device to two parts of the conduits and equipments under pressure. A first and a second sleeve which close two end portions of the flexible cable form, at the ends of the safety device, the first and second attachment eyelets. Two terminals are provided at the opposite ends of the flexible cable.