If you are a regular visitor to this site, you know I love to use the International Fire Code, which many states adopt in full or in some “revised” langauge as their “state fire/hazmat code”. One particular item that garners a lot of questions and comments is the IFC’s requirement that ALL hazardous materials (those with toxic or physical hazards) be in piping constructed per ASME B31.3 and labeled per ASME A13.1. This also includes a requirement that “Backflow prevention or check valves shall be provided where the backflow of hazardous materials could create a hazardous condition”. This OSHA case file is a good example of how this requirement would apply to a chemical process.
First, here are the IFC requirements for the piping, tubing, valves, and fittings…