Steel Tube Handbook

96 Dimensional tolerances Exact values are listed in corresponding standards. Approximate data are shown in the Table 42 of tolerances (page 97). Steel Elbows are made from steel shown in survey table at page 92. At standard DIN 2609 there is shown also steel qualification according to this standard. As a supplement of the survey there is listed also standard and steel grade of tube which is a part of pipeline together with elbow. Elbow verify according to requirements of standard NACE MR 0103, NACE MR 0175. C-equivalent calculating formula see page 103. Heat treatment, delivery condition and surface quality The elbows are made by hot forming process and they are delivered without heat treatment. Normalising includes normali- sing forming. Surface quality is corresponding to manufacturing process. Upon agreement - sand blasting of outside surface. End preparation Elbows are delivered with plain ends. Preparation of ends for welding (beveling) according to standards: – STN, ČSN 13 1075 – ASME (ANSI) B16.9 – DIN 2559 – EN 10 253 and other EN standards – NFA 29-032 and standards for pipes – ISO 6761 Testing Pipes as a raw material and finished elbows are tested according to corresponding standards. Marking The elbows are deliverd with marking: – without marking – colour marking – steel grade according to corresponding standard – stamping of data according to standard, customer‘s requirements or equipment possibilities (size of elbow). Surface protection The elbows are delivered without surface protection. Temporary protection with oil upon agreement. Packaging Fittings are packed in cartons, placed on wooden pallets, or in matalic box pallets. Certificates Certification in accordance with the following standards: STN, ČSN 42 0165, 42 0250, 42 0251 ASTM A234/A234, A420/A420M DIN 50049 – 2.2, 3.1.A, 3.1.B, 3.1.C EN 10 204 – for EN 10253-1 – 2.2 (non-specific testing) – for EN 10253-2 – 3.1.B (specific testing) eventually 3.1.A, 3.1.C, 3.2 (see also page 7) DIN T < 3 mm (Tvar 1) EN T < 3 mm ANSI (ASME) T < 3 (5) mm ČSN, STN T < 2,6 (3–4) mm (according method of welding) DIN T = 3–16 mm (Tvar 22) 2α = 40°–60°, c = do 2 mm EN T = 3–20 mm 1) α = 30° 0° +5° c = 1,6 ±0,8 mm ANSI T < 22 mm 2) (ASME) α = 37,5° ±2,5° c = 1,6 ±0,8 mm (c = 1/16 ±1/32 inch) ČSN, STN T = 3–20 mm 2α = 70° ±2° c = 1,5 +0,5 mm (T = 2,9–11 mm) Trimming the elbows ends: