... Heat transfer is fast, and heat output is less,and the ability of heat shock is better.4)Length tolerance ≤ ± ... Parallelism ≤ 0.03mm5)Good flatness, no deformation.6) the main role is antiseptic7)the surface treament: ZL 00 1 34170.7 PPC ... underwater steel oil, natural gas, water, heating the walls of the pipeline corrosionThe pipe Protect the environment,Save time.Accord to "Economy,Efficiency,Ecology, ...