A method of producing an annular insulating mineral fiber covering, comprises the following steps: producing a first non-woven mineral fiber web defining a longitudinal and a transversal direction parallel with the first non-woven mineral fiber web, moving the first non-woven mineral fiber web in the longitudinal direction, folding the first non-woven mineral fiber web transversely relative to the longitudianl direction and parallel with the transversal direction by decelerating the first non-woven mineral fiber web so as to produce an unsupported second non-woven mineral fiber web comprising ondulations including two sets of ondulation peaks extending in opposite directions relative to one another and relative to a plane of separation parallel with the longitudinal and transversal directions, separating the two sets of ondulation peaks from one another and from the second non-woven mineral fiber web along the plane of separation so as to produce two sets of curved half-coverings, and composing two half-coverings of the two sets of curved half-covering into the annular insulating mineral fiber covering. The invention also relates to a plant for producing an annular insulating mineral fiber covering, and an annular insulating mineral fiber covering.