Warn personnel, Identify contents and mark the directional flow for pipes carrying hazardous contents. Pipe markers should be placed at frequent intervals along piping systems, and should be clearly legible at a distance. Visible colors and bold lettering on the pipe marker are designed to meet or exceed ASME (ANSI) A13.1-2007 recommendations for size, color and visibility for flammable fluids. Available in Self Stick adhesive Vinyl, or a pre-coiled wrap made of heavy-gauge 20-mil rigid vinyl plastic.