TECHNICAL SPECIFICATIONS FOR BARE LINEPIPE FOR FIREWATER SERVICE

Transcription

1 TECHNICAL SPECIFICATIONS FOR BARE LINEPIPE FOR FIREWATER SERVICE A) IS: 3589 GRADE FE 330 This tender specification establishes the minimum requirements for the manufacture of IS: 3589 Grade Fe330 Bare line pipe. Unless modified and referred by this Specification, the requirements of IS: 3589:2001 shall prevail. Clause wise reference to IS: 3589:2001 is given herein below.vendors to supply line pipes strictly in accordance with the specifications given below. Wherever only brief description of the Clause is given, the detailed description given in the particular clause referred in IS: 3589:2001 shall be followed and shall be applicable. 5 Designation 330. The Bareline pipes supplied by the vendors shall be of Grade Fe 6 Quality of Steel Pipes shall be manufactured with steel produced by the Open hearth or electric furnace or one of the basic oxygen processes. 7 MANUFACTURE OF THE PRODUCT The pipes shall be manufactured by one of the following processes: Specifications Page 1 of 9

2 7.2 Electric Resistance Welded Pipes: The pipes shall be manufactured from plate or sheet welded continuously by the passage of an electric current across the abutting edges longitudinally. The external weld bead shall be removed completely. 7.3 Submerged Arc Welded Pipes: The pipes shall be manufactured from plate or sheet with either a single longitudinal seam welded across the abutting edges by an automatic submerged arc welding process using atleast two runs, one of which shall be on the inside of the pipe. 7.4 Repair by Welding Injurious defect in pipe wall, provided their depth does not exceed one third of the specified wall thickness, shall be repaired by welding Defects in the welds, such as sweats and leaks, unless otherwise specified may be repaired or piece rejected at the option of the manufacturer for submerged arc welded pipes Welds of the electric resistance welded pipes may be repaired only by agreement between HPCL and the manufacturer. Manufacturer to submit his position on this aspect in his Unpriced Bid. If nothing said in unpriced bid then NO repair shall be allowed and piece shall be considered as rejected. Specifications Page 2 of 9

3 Repairs of this nature if accepted by HPCL shall be made by completely removing the defect, cleaning the cavity and then welding All repaired pipes shall be retested hydraulically in accordance with Cl CHEMICAL COMPOSITION Ladle Analysis The ladle analysis of steel shall be as given in Table 2. The analysis of steel shall be carried out by the method specified in IS 228. However, where the method is not given in IS 228 and its relevant parts. However, if the method in not found in IS 228 & its relevant parts then the referee method shall be as agreed to between the HPCL and the manufacturer. In this aspect manufacturer shall spell out their method in case of any variation/deviation at the unpriced Bid stage only. Product Analysis Permissible variations in the case of product analysis from the limits specified in Table 2 shall be as given in Table 3. 9 MECHANICAL PROPERTIES The mechanical properties of the linepipe covered in this specification shall be tested for the following: Specifications Page 3 of 9

4 9.1 Tensile Strength: As per IS Flattening or Bend Test: Flattening test for ERW Pipes: As per IS Guided Bend Test (For SAW Pipes): As per IS HYDRAULIC PRESSURE TEST Each pipe shall be hydraulically tested at the manufacturer s works before the pipe is released from the vendor s works The hydraulic test pressure shall be the pressure calculated as per the following formula: P = 2ST/D Where in Mpa. P= hydraulic test pressure Mpa. D = specified outside dia of the pipe in mm. T = specified thickness of the tube in mm, and S =stress 60% of the specified minimum yield stress The maximum test pressure to be limited to 5 Mpa wherever applicable The hydraulic test pressure shall be applied for minimum of 5 seconds. 11 DIMENSIONS AND MASS PER METRE RUN OF PIPES Specifications Page 4 of 9

5 11.1 Preferred outside diameter and thickness of the pipes are specified in the Table 5. The table also provides the nominal mass per meter run of the pipes against each dimension. 12 TOLERANCES 12.1 Positive Tolerance on mass shall be + 7.5% and no negative tolerance shall be permitted. The negative tolerance on Wall thickness shall be zero and the positive tolerance shall be as per IS: General The tolerance on the dimensions of the pipes shall be as specified in 12.3 and 12.4 except that the negative tolerance on wall thickness shall be zero Outside Diameter, Thickness and Height of Internal Weld Bead or Reinforcement The tolerance on outside diameter shall include ovality except for submerged arc welded pipes. The tolerance of the specified outside diameter of pipe wall shall be as given in Table 6. Specifications Page 5 of 9

6 TABLE 6: Outside Dia (For all sizes) Tolerance For ERW & SAW pipes +.75 %; -0% Thickness The thickness tolerance shall not apply to the weld area. The maximum height of the weld bead on the internal surface of the pipe shall not exceed 60 percent of nominal wall thickness. The tolerance on the specified wall thickness shall be as follows: ERW pipe : +10 %; - 0% SAW pipe : + 20 %;-0% Ovality Ovality shall not exceed 1 percent of the specified outside diameter for pipes having diameter to thickness ratio not exceeding Random Length Specifications Page 6 of 9

7 ALL THE PIPES AS PER SCHEDULE OF QUANTITIES SHOULD BE SUPPLIED IN DOUBLE RANDOM LENGHTS OF 7-14 METERS Straightness Finished pipe shall not deviate from straightness by more than 0.2 percent of the total length Checking should be carried out using a taut string or wire from end to end, along the side of the pipe to measure, the greatest deviation. 13 NUMBER, SELECTION AND PREPARATION OF SAMPLES AND TEST PIECES 13.1 The procedure for sampling of pipe for various tests and criteria for conformity shall be as given in IS The test samples shall be cut from pipes in the final condition of supply One set of mechanical tests as specified in cl no.9 shall be carried out from samples taken of each tube For the tensile test, the dimensions of the test piece shall comply with the appropriate requirements of IS For Specifications Page 7 of 9

8 welded pipes the tensile test piece shall not include the weld unless the pipe is tested in full section. NOTE- For the tensile test, the piece may be taken either longitudinally or transversely from the pipe at the option of the manufacturer For a bend test on the weld, two pieces shall be prepared, one for a face bend test and one for a root bend test. Both test pieces shall be not less than 40 mm wide and cut perpendicular to the weld line from one end of each selected pipe so that the weld is in the middle of the test piece and 90 to the longer sides. The weld reinforcement shall be removed from both faces. The length of the test pieces shall be selected by the manufacturer to suit the equipment used for the test. NOTE- The test pieces may be flattened before testing. 14. VISUAL INSPECTION, APPEARANCE AND WORKMANSHIP 14.1 The pipes shall be clean and free from such defects as can be established by visual inspection in accordance with the IS:3589 standard It shall be permitted to dress by grinding or machining surface marks and imperfections such as scabs, seams, tears, laps, silvers or gouges provided that the thickness of the tube after dressing does not fall below the nominal thickness by more than the tolerance specified in this standard. Specifications Page 8 of 9

9 14.3 All dressed areas shall lend smoothly into the contour of the pipe For pipes which have a thickness to diameter ratio equal to or less than 0.03, isolated dents shall not be cause for rejection provided that they do not exceed a depth greater than 6mm maximum for pipes below 610 mm OD measured as a gap between the point of the dent and a prolongation of the original contour of the pipe. The length of the dent in any direction shall not exceed one half the pipe diameters The ends shall be cut nominally square with the axis of the pipe and shall be free from excessive burrs. 14 Conditions of supply Bare pipes should be supplied without any coating. 17 The ends shall be plain as per IS: 3589 and suitable for sleeve joints. 18 Marking : As per IS BIS Standard Mark All the pipes supplied vide this Specifications shall be duly marked with the Standard Mark. Specifications Page 9 of 9