NEW HINDUSTAN TUBES PVT. LTD.

Indian Standard » SPECIFICATION for Lancing Pipes


1. Manufacture


  • This Indian Standard was adopted by the Indian Standards Institution on 30 November 1982, after the draft finalized by the Steel Tubes,Pipes and Fittings Sectional Committee had been approved by the Structural and Metals Division Council.
  • This Indian Standard has been prepared to meet the requirements of lancing pipes used by steel industry.
  • Requirements for ceramic and other special coating to enhance the life of the pipes will be added in due course after collecting the necessary data.
  • This standard contains clauses 2.4, 11.1 and 12.1 Which call for agreement between the purchaser and the manufacturer.
  • For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated,expressing the result of a test or analysis, shall be rounded off in accordance with IS : 2-1960. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.

2. Scope


  • This standard covers the requirements of butt-welded, screwed and socketed and plain end mild steel pipes intended for use on oxygen lancing.

3. Terminology


  • For the purpose of this standard,the following definitions shall apply.
  • For the purpose of this standard,the following definitions shall apply.
  • Black Pipe - Pipe as manufactured, but without any subsequent surface treatment.
  • Length of Screwed and Socket Pipe - The length of the pipe inclusive of the socket.
    • Note 1. The length of the pipe inclusive of the sockets means the pipe length measured with socket fitted at one end to handling-tight.
    • Note 1. Handling tight means that the socket is so tight fitting that it should not fall down during handling or transit.
  • Nominal Bore - A size reference denoting the approximate bore of the pipe. For each size of pipe, the outside diameter is fixed by the corresponding screw thread dimensions of                              IS : 554-1975 and therefore, the actual bore of each size of pipe will vary according to the thickness.
  • Random Length - Normal manufacturing lengths which may vary over a range of several meters. Alternatively, a length range agreed to between the purchaser and the                                    manufacturer.
  • Socket - The screwed coupling utilized in joining the pipes together.
    • Note 1. The term 'socket' is synonymous with the term 'coupler'.
  • Pipe(Tube) - A long, hollow, open-ended object of circular or other cross-section. The term 'pipe' is synonymous with the term 'tube'.

4. Designation


  • Mild steel pipes covered by this standard shall be designated by their nominal bore, and shall be further classified as 'light','medium' and 'heavy' depending on the wall thickness.
  • Mild steel socket shall be designated by the respective nominal bore of the pipe for which it is intended.

5. Supply of Material


  • General requirements relating to the supply of mild steel pipes and sockets shall conform to IS :1387-1967.
  • Lancing pipes shall be supplied with any of the following combinations as specified by the customer:
        • Plain end, and
        • Both ends screwed and one end socket

6. Manufacture


  • Pipes shall be manufactured from mild steel made by open hearth, electric or any of the oxygen processes.
  • Steel pipes and sockets shall be manufactured by one of the following processes:
        • Continuous oxy-acetylene gas welded pipes(OAW),
        • Electric resistance welded(ERW),
        • High frequency induction welded(HFIW), and
        • Hot-finished welded (HFW).
    • Note 1. Pipes made by manual welding are not covered by this specification.
    • Note 2. Hand welding of sockets may be permitted provided the test requirements for the sockets covered by the standard are complied with.
    • Note 3. Sockets may also be manufactured from rods provided the test requirements for the sockets covered by the standard are complied with.

7. Dimentions


  • The dimentions of pipes shall be in accordance with Table 1,2 and 3 subject to the tolarences permitted in 8. Dimentions of sockets shall be in accordance with Table 4.

8. Mass


  • Nominal masses of 'light','medium',and 'heavy' black pipes shall be as specified in Table 1,2 and 3 respectively.


Table 1. Dimensions and Nominal Masses of Black Steel Pipes (Light)
Nominal Bore Outside Diameter Thickness Mass of Black Pipes
mm Max (mm) Min (mm) mm Plain End (kg/m) Screwed and Socketed (kg/m)
6 10.1 9.7 1.8 0.361 0.364
8 13.6 13.2 1.8 0.517 0.521
10 17.1 16.7 1.8 0.674 0.680
15 21.4 21.0 2.0 0.952 0.961
20 26.9 26.4 2.35 1.41 1.42
25 33.8 33.2 2.65 2.01 2.03
Note-Dimensions and masses are in accordance with ISO 65-1981.
Table 2. Dimensions and Nominal Masses of Black Steel Pipes (Medium)
Nominal Bore Outside Diameter Thickness Mass of Black Pipes
mm Max (mm) Min (mm) mm Plain End (kg/m) Screwed and Socketed (kg/m)
6 10.6 9.8 2.0 0.407 0.410
8 14.0 13.2 2.35 0.650 0.654
10 17.5 16.7 2.35 0.852 0.858
15 21.8 21.0 2.65 1.22 1.23
20 27.3 26.5 2.65 1.58 1.59
25 34.2 33.3 3.25 2.44 2.46
Note-Dimensions and masses are in accordance with ISO 65-1981.
Table 3. Dimensions and Nominal Masses of Black Steel Pipes (Heavy)
Nominal Bore Outside Diameter Thickness Mass of Black Pipes
mm Max (mm) Min (mm) mm Plain End (kg/m) Screwed and Socketed (kg/m)
6 10.6 9.8 2.65 0.493 0.496
8 14.0 13.2 2.9 0.769 0.773
10 17.5 16.7 2.9 1.02 1.03
15 21.8 21.0 3.25 1.45 1.40
20 27.3 26.5 3.25 1.90 1.91
25 34.2 33.3 4.05 2.97 2.99
Note-Dimensions and masses are in accordance with ISO 65-1981.
Table 4. Dimensions of Sockets
Nominal Bore Outside Diameter (min) Length (min)
6 15 19
8 18 27
10 22 28
15 27 37
20 32.5 39
25 39.5 46


9. Tolarances on Thickness and Mass


  • The following manufacturing tolerances shall be permitted on the pipes and sockets:
    1. Thickness Light pipes
    Medium and heavy pipes
    ± Not limited 8 percent
    ± Not limited 10 percent
           
    2. Masses ( No limit on + side) Light pipes
    Medium and heavy pipes
    For quantities per load of 10 tones, Min (light series)
    For quantities per load of 10 tones, Min (medium & heavy series)
    ± Not limited 8 percent
    ± Not limited 10 percent
    - 5 percent
    - 7.5 percent
    • Note 1. For the purpose of weighting lots of 10 tones or more, the material may be divided into convenient sub-lots and weighted separately. Finally the tolerance may be               applied to the total weight of lot.

10. Joints


  • All screwed tubes and sockets shall be supplied with pipe threads conforming to IS : 554-1975. Gauging practice shall be in accordance with IS :8999-1979.
        • Unless specified otherwise, pipes shall be supplied screwed with taper threads and sockets with parallel threads.
        • However, in the case of 'light' tubes, the application of taper pipe threads may be modified by permitting the outside diameter of the pipes to be within the limits shown in col 2
          and 3 of Table 1.Where the pipe approaches the lower limit of outside diameter, some incomeplite threads (perfect at root and imperfect at the crest) may be expected from
          and beyond the gauge plane. such incomplete threads shall not be regarded as justification for rejection of the pipes. Also the minimum length of threads in 'light' pipes shall
          be 80 percent of that specified in IS : 554-1975.
  • Each pipe shall be supplied with one socket and one plastic protective ring. The ends of sockets shall be chamfered internally to prevent damage to the leading thread. Tapping of sockets shall be done from one end only.

11. Lengths


  • Random Length - The pipes shall be supplied in random lengths from 4 to 8 meters, unless otherwise agreed to between the manufacturer and the purchaser.

12. Hydraulic Test


  • The pipes shall be supplied in random lengths from 4 to 8 meters, unless otherwise agreed to between the manufacturer and the purchaser.
  • Pipes shall withstand a test Pressure of 5 MPa(see NOTE) without showing defects of any kind. The pressure shall be applied by approved means and maintained sufficiently long for proof and inspection. The testing apparatus shall be fitted with an accurate pressure indicator, and provision shall be made for its accuracy to be verified by the purchaser,if required.
    Note - 1 Mpa=0.102kgf/mm2     10.2kgf/cm2

13. Test on Finished Pipes and Sockets


  • The following tests shall be conducted by the manufacturer on finished pipes and sockets.
  • The tensile strength of length, cut from selected pipes when tested in accordance with IS :1894-1972 shall be at least 320 MPa
    ( 320 N/mm2 )
  • The elongation percentage on a gaguge length of 5.65√So .(where So is the original cross-sectional area of the test specimen) shall be not less than 12 percent.
  • Bend Test on Pipes - When tested in accordance with IS :2329-1963, the finished pipes shall be capable of withstanding the bend test without showing any signs of fracture or failure. The pipes shall be bent with the weld at 90° to the plane of bending. The pipes shall not be filled for this test.
    When tested in accordance with IS :2329-1963, the finished pipes shall be capable of withstanding the bend test without showing any signs of fracture or failure. The pipes shall be bent with the weld at 90° to the plane of bending. The pipes shall not be filled for this test.
  • Expansion Test on Sockets - At the option of the manufacturer any one of the tests described in bellow.

    Drift Expanding Test - It shall be carried out on sockets,blacks for sockets in accordance with IS : 2335-1963 on a conical mandrel having an include taper on diameter 1 in 16 and the minimum increase in outside diameter after expansion shall be 2 percent.

    Taper Screw Plug Test - Sockets shall be capable of withstanding the expansion test as described below without showing any sign of fracture or failure. The test shall consist of screwing the selected socket on a taper screw plug.
    The threads of the socket shall be thoroughly clean and free from foreign matter. Should the threads show sign of burr, this shall be removed by rotating the socket with both hands. The socket shall then be further rotated five complete turns beyond hand tightness, either by means of a pipe wrench of an adequate length to operate the test with gradual turning or by a power machine giving an appropriate leverage. The wrench shall not be hammered.
    The Plugs shall be manufactured from steel and shall be hardened to give a Vickers hardness between 700 and 800 HV when determined by applying a load of 30kgf in accordance with IS :1501-1968.
    The plugs shall be in accordance with the dimensions given in Table 5. The thread shall be ground after the plugs are case hardened, and the thread form and angle of taper shall be in accordance with the appropriate dimensions and tolerances specified in IS :554-1975.
    For routine testing, use may be made, if so desired, of unhardened steel plugs in accordance with dimensions given in Table 5 and having 1975.
    In cases of dispute, however, the test shall be carried out with the hardened plugs specified in above

14. Workmanship


  • The pipes shall be cleanly finished and reasonably free from scale.They shall be reasonably straight, free from cracks,surface flaws,laminations and other defects.The screw threads of screwed pipes and sockets shall be clean and well cut. The ends shall be cut cleanly and square with the axis of the pipe.

15. Sampling of Tubes and Sockets


  • Lot - For the purpose of drawing samples, all lancing pipes bearing the same designation and weight classification and also manufactured under a single process shall be grouped together to constitute a lot. Each lot shall be sampled separately and assessed for conformity to this specification.
  • Sampling and Criterion for Conformity - Unless otherwise agreed to between the manufacturer and the purchaser the procedure for sampling of pipes for various tests and criteria for conformity shall be as given in IS : 4711-1974.

16. Marking


  • Each pipe or each bundle of pipes shall carry legibly the manufacturer's name or trade-mark.
  • The different classes of pipes shall be distinguished by color bands which shall be applied as follows before the pipes leave the manufacturer's works:
         'Light' pipes Yellow
         'Medium' pipes Blue
         'Heavy' pipes Red
  • The pipes or each bundle of pipes may also be marked with the ISI Certification Mark.
    • Note 1. The use of the ISI Certification Mark is governed by the provision of the Indian Standards Institution(Certification Marks)Act and the Rules and Regulations made the reunder. The ISI Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well-defined system of inspection, testing and quality control which is devised and supervised by ISI and operated by the producer. ISI marked products are also continuously checked by ISI for conformity to that standard as a further safeguard. Details of conditions under which a licence for the use of the ISI Certification Mark may be granted to manufactures or processors, may be obtained from the Indian Standards Institution.
  •  Normal Bore(mm)
     Gauge Diameter(mm)
    Threads per 25.4 mm
    Tolerance on Total Number of Threads
    A
    B
    C
     D
             
         
    6 9.728 28 2 1.8 13 11 7
    8 13.157 19 2 2.8 19 13 10
    10 16.662 19 2 2.8 19 16 13
    15 20.955 14 2 3.6 25 19 14
    20 26.441 14 2 3.6 25 29 17
    25 33.249 11 2 4.6 32 29 21

17. Packing


  • Unless otherwise agreed to between the manufacturer and the purchage, the pipes shall be bundled for the transport and packed in accordance with IS : 4740 1979. However, the pipes of same size and class shall be bundled together and the capped ends shall be protected by gunny cloth. Each smallest bundled shall contain preferably not more than 20 pipes.

18. Coating


  • The lancing pipes:
         a) shall have no internal coating,
         b) shall be free from grease and oil, and
         c) may be externally coated as specified by the purchaser.

19. Enquiry and Order


  • The following information shall be furnished by the consumer while ordering the pipes:
         a) Class of pipe,
         b) Nominal bore,
         c) Length,
         d) End condition, and
         e) Packaging requirements.

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