A releasable connector for interconnecting a first part and a second part, at least one of the parts being subjected to high stresses in particular of vibratory origin and of thermal origin, the connector comprising a sealing ring compressed between the two parts, a main lip formed on the first part to be interconnected, and at least one connection part for exerting a retaining action on the main lip relative to the second part to be interconnected and for compressing the sealing ring. The connector further includes an intermediate ring provided with a flange and constituted by at least two lengths, the intermediate ring being interposed between the main lip and the connection part and being made of a material of low thermal conductivity. The connection part has a thin wall provided in the form of a bellows for adjusting the elasticity of the connection and the thermal barrier constituted by the connection, the thin wall being situated between a first fixing portion for fixing on the second part and a cylindrical second portion having an inside diameter greater than the outside diameter of the main lip. The flange of the intermediate ring bears against the cylindrical second portion of the connection part.