... professional manufacturer of siphon,drainage,ground source. Black HDPE pipe is good for anti-UV, anti-aging, anti-corrosion ... ,won't fouling for long-term using.• polyethylene pipe can be weld,fittings and pipes into one,without ... reliable.• Good flexibility,small tube can be winding,pipe can be meandering along the ditch.resist the geological ... drainage,the same layer drainage system. HDPE pipe clamp