Detailed Product Description Our plan getsthe special equipment manufacturing licenses which awarded by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. All pipes are produced mainly according to SY/T5037-2000,GB/T9711.1-1997, APISpec5L standards. And the material adopts Q235, Q345, 10#, 20#, 16mn, L245, L290, L360,X42-X70. Our ...