1.1 This specification covers three grades of seamless and welded zirconium pipe.1.2 Unless a single unit is used, for example corrosion mass gain in mg/dm2, the values stated in either inch-pound or SI units are to be regarded separa This specification covers seamless and welded zirconium and zirconium alloy pipe. The pipe is furnished in three grades as follows; grade R60702- unalloyed zirconium, grade R60704- zirconium-tin alloy, and grade R60705- zirconium-niobium alloy. Seamles