(a) Heated Rooms.      
        (1) A chlorine and sulfur dioxide system that uses 150 pound cylinders must be located indoors at a minimum room temperature of 65 degrees Fahrenheit. This provision applies to all chemical feed equipment, including all connected cylinders, the chlorinators, and the sulfonators.       
        (2) An unconnected chlorine or sulfur dioxide cylinder may be stored outdoors, but the cylinder must reach a surface temperature of at least 65 degrees Fahrenheit before it is connected to a system.       
      (b) Heating Blankets.      
        (1) Heating blankets on chlorine gas cylinders are prohibited.       
        (2) A heating blanket may only be placed on a sulfur dioxide cylinder in a temperature-controlled room to increase the temperature inside the cylinder to above the ambient room temperature.                  (A) A heating blanket on a sulfur dioxide cylinder must include a mechanism that ensures that a blanket does not heat a cylinder above 100 degrees Fahrenheit. The engineering report must include a calculation that documents the setting for a heating blanket to maintain a sulfur dioxide cylinder temperature of less than 100 degrees Fahrenheit.                   (B) A cylinder with a heating blanket that is connected to a dechlorination system must have a downstream pressure-reducing valve.                   (C) A sulfur dioxide system must be capable of automatically deactivating a heating blanket if high pressure is detected in the cylinder or the delivery system.         
      (c) Outdoor Storage. If a 150 pound cylinder is stored outdoors, it must be kept in a storage structure that:      
        (1) protects the cylinder from direct sunlight; and       
        (2) allows safe removal and replacement of the cylinder.       
     Source Note:        The provisions of this §217.275 adopted to be effective August 28, 2008, 33 TexReg 6843; amended to be effective December 4, 2015, 40 TexReg 8254