Improve facility safety with Geothermal Loop Return Pipe Markers. Outfit your facility with standard pipe markers to convey important information about Various Water pipe contents and potential hazards. These pressure-sensitive vinyl pipe markers exceed ANSI/ASME A13.1 and OSHA standards for general facility pipe marking. Choose from a variety of color schemes, sizes, flow directions, and piping abbreviations of your preprinted labels that fit your needs.