The present invention relates to devices and methods for containing gas leaks in pipelines. In particular, the present invention describes a device for eliminating gas leaks by sealing a gas leak in an expansion joint arranged between two pipes misaligned with each other, the device comprising a metallic structure comprising a sealing blanket, in which the metallic structure and blanket fully enclose the expansion joint using cables. In addition, the present invention describes a gas leak elimination device for sealing a gas leak in an expansion joint arranged between two aligned pipes, the device comprising a sealing blanket, steel cables, straps and fastening elements to fully enclose the expansion joint.