Where should a permanently marked information sign be placed for a system supplying the antifreeze loop?

The correct location for a permanently marked information sign in a system supplying an antifreeze loop is at the system control riser. This is because the control riser serves as the central point for managing and controlling the fire protection system, including the antifreeze loop. A sign placed here ensures that crucial information regarding the antifreeze system is easily accessible for maintenance personnel and emergency responders.

In the case of the antifreeze system, it is vital to indicate the type of antifreeze used, the concentration level, and any other pertinent information related to the system’s operation and safety. Positioning the sign at the control riser keeps this important information centralized and helps facilitate effective inspection and maintenance.

Although alternatives such as placing signs at the main supply line or fire pump could provide some degree of information, they would not serve the specific purpose of highlighting critical details about the antifreeze loop in the manner intended under NFPA guidelines. Each sprinkler head would be inappropriate for this marking since general operational information would be more relevant at a central point rather than at each individual sprinkler location.