... from 5mm-30mm ,3 The fabrication is carried out according to the international standards of API5L PSL1 ,API5CT, ASTM ,DIN, and national ... 1~2, SY/T5037 and SY/T5040..4 Strictly adhering to ISO9001:2000 Standards , our company established Quality Management System and ... have also settled down control processes from the material purchase to the entire production and also the inspection, development of the ...