Method for forming a sealing element from extruded thermoplastic rods includes the steps of machining one or more extruded thermoplastic rods, each having a first and a second end, in a desired shape; bending the one or more machined thermoplastic rods into a circular structure at ambient temperature while keeping the stress in the one or more thermoplastic rods below the yield point; joining the first and second end faces of the thermoplastic rods to form the sealing element. A method for replacing and repairing a sealing element of a swivel is also described.