1) Standard: API Standard:ASTM A106.ASTM A53,ASTM A135,ASTM A179,ASTM A214,ASTM A192,ASTM A226,ASTM A315,ASTM A178,ASTM A210,ASTM A333,ASTM A355,ASTM A369,ASTM A334 ASTM/ASME A312/SA312, ASTM/ASME A213/SA213, ASTM A269,ASTM 511,API5L,API5CT, GOST 9940,GOST 9941,JIS G 3459, JIS GS3463, GS3467, JIS G3448, DIN EN 10216-2006(DIN 17458) , DIN EN 10297-2006(DIN 17456) etc. 2) Steel Grade: ASTM A106 GRB,A53 GRB. API 5L GRB,API 5 CT N80,K55,A335 P11.P91,DIN ST52,ST44,ST35.8,ST37,ST42,ST45 3) Outside Diameter: 10.3 - 914.4 mm 4) Wall Thickness: 1.73-50mm 5) Application: The products are widely used in fertilizer, petroleum, central-station, boiler, power station, shipping military, chemical industry, environment protection, traffic, metallurgy and mine, printing and dyeing, food industry, medical equipment, and so on.