Historical clue formulations

• Contractor's pipe material, for short — 2025-05-21
• Plastic used in piping, for short — 2022-12-27
• Plastic pipe material, in brief — 2022-03-01
• Plumber's pipe material, in brief — 2021-11-02
• Plastic pipe material, for short — 2018-12-25
• Pipe material, for short — 2011-04-10
• Plastic used in piping — 2011-02-27
• Common pipe material, briefly — 2010-10-12
• Piping compound, briefly — 2007-09-18
• Insulation ingredient, for short — 2000-03-01