Carbon Steel Pipe with High Quality 1.WT:4-70mm OD:25-370mm 2.Certification:API ... -exchanger tube- Pipeline seamless pipe10-530×1.5-36 high-pressure seamless pipe for chemical fertilizer equipment 20,16Mn,Q345GB6479 ... industrial dilivery(gas,water,oil)60-630×1.53-40 Rectangular TubeQ195,Q235,Q345,20#GB/T6278-2002 Structure, decoration, construction20 ... GR.B/A106 GR.B Carbon Steel Pipe with High Quality