Type K copper pipe is the thickest-walled version of copper tubing, designed for heavy-duty applications. It is primarily used for underground water mains, commercial plumbing, fire protection systems, and HVAC installations where high pressure and durability are required. When sourcing, ensure the pipe meets ASTM B88 standards, which define the dimensions and tolerances for seamless copper water tube. The material should be 99.9% pure copper (C12200) to ensure maximum corrosion resistance and conductivity.