IS 1239 is the definitive Bureau of Indian Standards (BIS) code for mild steel tubes used for water, gas, and steam.
Classification: Similar to BS1387, it classifies pipes into three color-coded classes based on wall thickness:
Light (Yellow Band)
Medium (Blue Band)
Heavy (Red Band)
Importance: Compliance with IS 1239 is mandatory for plumbing safety in India, ensuring pipes can handle internal water pressure without bursting.