A pyromechanical disconnecting device that includes a housing having a receiving space for an ignition element and a supporting floor. A disconnecting tool is disposed in the housing and movable along a path toward a disconnecting point of a current conductor rail. Also disposed in the housing is an ignition element adapted to propel the disconnecting tool along the path to sever the current conductor rail. The ignition element includes an end having a conical flank facing the supporting floor of the housing. An elastic sealing element is arranged about the conical flank and the supporting floor to act as an axial tolerance compensator between the ignition element and the supporting floor of the housing.