These requirements apply to hardware for horizontally sliding fire doors which have demonstrated in fire tests fire-resistive properties warranting their use with two-ply and three-ply tin-clad fire doors tested in accordance with the Standard for Fire Tests of Door Assemblies@ UL 10B (NFPA No. 252). Requirements for the location and time rating are contained in codes@ such as the International Building Code (IBC). The method of installation required for fire doors is not included in these codes. Requirements for the details for the installation of horizontally sliding two-ply and three-ply tin-clad fire doors are included in the Standard for Fire Doors and Other Opening Protectives@ NFPA 80. The hardware included in these requirements is designed for mounting standard two-ply and three-ply tin-clad horizontally sliding fire doors for protection of openings not exceeding the dimensions for the hourly classifications indicated in Table 1.1. These requirements do not cover automatic releasing or closing mechanisms.