a cover of a centrifugal compressor intended to be rigidly connected to a turbomachine housing , which includes a plurality of ports , is provided . the cover further includes a fastening device for fastening the cover to the housing . a portion of the fastening device is located upstream relative to the ports and can be accessed by a fastening tool through at least one of the ports of the cover . a turbomachine uses this cover to form a sealed space , in particular with a view to collecting air .