THERMAL INSULATING MATERIAL MADE OF THERMOPLASTIC OR ELASTOMERIC FOAM IN THE FORM OF PIPES, TUBES, OR CYLINDRICAL SLEEVES WHICH CAN BE OPENED AND CLOSED ALONG A LONGITUDINAL SLOT, WITH OR WITHOUT SUPPORT SEGMENT INSERTS MADE OF RIGID FOAM; PIPE SUPPORTING ELEMENTS CONSISTING OF A THERMAL INSULATING MATERIAL MADE OF THERMOPLASTIC OR ELASTOMERIC FOAM, WITH OR WITHOUT SUPPORT SEGMENT INSERTS MADE OF RIGID FOAM