Hi Mike,
Type L (blueline) copper is the grade required for outside direct burial water pipe. Larger wall thickness and temper hardness over interior grade Type M (redline) reduces triboelectric static DC buildup erosion on pipe from frictional water flow and high chlorine corrosive effects combined. Stanford University had a study done on the local medical center near campus and results showed a copper leaching from copper water pipes and facility waste use to be well over 0.18 lbs per day. Remedies were mentioned to lower flow rates, water oxygen content and change water pH. (1991-1994 Copper corrosion study by Kennedy-Jenks Consultants, Palo Alto, CA).
I hope this helps. ben jacks
|