Pipe Identification Guide
ASME (ANSI) Standard A13.1-2007
The ASME (ANSI) Standard for pipe identification is a widely used
guideline in determining pipe identification requirements. The
purpose of the standard is to:
• “assist in identification of hazardous materials conveyed in piping
systems and their hazards when released into the environment.”
• “Pipes are defined as conduits for the transport of gases, liquids,
semi-liquids or fine particulate dust.”
ASME (ANSI) Size Recommendation. The legend (name of pipe content) and directional flow arrow is the primary means of identifying pipe content. A13.1-2007 standard makes recommendations as to the size of letter height
and length of color field for various pipe diameters.
ASME (ANSI) Color Recommendations Unmarked pipes mean danger – to both life and property. Numerous injuries have occurred through ignorance of pipe contents, particularly when outside agencies are called in under emergency conditions.