Cerro 3/4" Inner Diameterx20' Type L Hard Copper Tube has a maximum working pressure of 1002 psi. ASTM compliant and NSF certified, this durable tube is suitable for interior gas, steam, and oil lines, as well as panel heating. Its Alloy C12200 (DHP) construction meets industry standards and is NSF and ANSI Standard 61 certified. Backed by a 1-year warranty.