Abstract: A unique design for improved creep strength with a leakage-free structure is presented for manufacture of creep-resistant pressure relief device (PRD) of valves or cylinders or any pressure vessels as a fire protection safety device, the new design being the combination of geometrical configuration of PRD body shell and composite technology wherein the relatively weak matrix phase is dispersed with strong reinforcing agent and such composite mixture of matrix phase/reinforcing agent is contained in a nonslip structure of PRD cavity with a length/diameter ration being greater than about one such that the external load is transferred to the PRD structural body via stress transfer mechanism through reinforcing agents. The PRD's or fuse plugs fabricated by techniques of the present invention exhibit pronounced creep strength and show no gas leakage under high pressure/elevated temperature conditions realized during fires.