Platform framing shall be designed for all dead loads, equipment loads, and a live load of at least 1200 kg/m2 live load. Vertical deflection of framing members shall not exceed 1/300 of their span length, or a maximum of 20 mm, whichever is less. All other design requirements shall be in accordance with the AISC Manual of Steel Construction. Each platform shall have lateral bracing as required or rigidity and stability.
Stair treads shall be 4 mm thick steel, serrated, galvanized, 300 mm width and 40 mm channel height. Stair framing, platform framing, kickplates and all supports and brackets for stair and platforms shall be ASTM A36 with galvanized.
Tanks shall be provided with walkways extending from the upper stair loading platform/ladder loading platform to the center of the roof for the maintenance of roof-mounted accessories, manhole and other roof mounted appurtenances. The walkway shall be minimum 1 meter wide. Roof handrailing shall extend on both sides of the roof walkway and completely around the working area at the center.
In addition to the requirements of tank design code, fixed ladders and cages, railing and toe boards, etc., shall meet the safety requirements of ANSI A12.1, A14.3, A64.1 and the applicable OSHA requirements.