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Recent content by pdprao

  1. pdprao

    Gauging pig dimensions

    A Natural Gas Pipe line is constructed with several( 24 Nos) 18"NB 6D hot induction bends for thermal expansion loops . The Induction bends are tested with gauge plates at the time of manufacture of bends at shops. The gauging checks at shop used pig with two gauge plates mounted on the...
  2. pdprao

    Flange Rating

    One need to refer and understand the standard ANSI B 16.5 which defines the terms" Primary pressure" and" Primary temperature" for various Flanges ratings. ANSI B 16.5 Flange ratings are designated as Class 300 #, class 600# ,etc . For Flange Pressure rating class 150 #,300#, 400# etc ...
  3. pdprao

    Liquid Pipeline Thermal Relief

    It appears the thermal relief valve is doing its intended function. Probably what needed is to review the materials of TRIM and improvment of properties for longer life. A pressurized overriding tank with suitable compressible gas such as Argon/Nitrogen may be a solution which needs a...
  4. pdprao

    Hydro-test methodology for Above ground laid 18" NB natural gas pipe line.

    Observations of MrDewe6 are very relevant about code inadequacy . Mr Biginch remarks on" Visual examination" needs some comments. Various ASME Codes of Pr vessels and Piping calls for Visual examination of Weld joints and pressure boundary at Design Pressure for absence of any evidence of...
  5. pdprao

    Using existing building steel for piping supports

    Usually it is a very common problem which has no simple solution . It is very important to consider the degree of pipe line loads, size of the structural members and original contemplated loads on the structural members.Many times the design & drawings will not be readily available for old...
  6. pdprao

    Piping weldolet Branch connection

    Radiography on 2" weldolet will not give any meaningful results and it is not a code accepted practice. If possible, you can carryout the re-hydro-test on the the new line. (which may not be feasible too) You can follow the following steps as additional examination and request for waiver...
  7. pdprao

    Hydro-test methodology for Above ground laid 18" NB natural gas pipe line.

    Mr Big Inch: In line no 3 of above thread , please note to read as " B31.8" in place of "B31.1" which is a typographical error .
  8. pdprao

    Hydro-test methodology for Above ground laid 18" NB natural gas pipe line.

    To clarify to Mr Biginch 1 B31.8 does not exclude a/g pipe lines . Agreed. But it also does not treat the A/g pipe line subject . Basically it appears , its focus is on underground pipe lines. 2 Visual Examination: Visual examination as per ASME pressure vessels code and other...
  9. pdprao

    Hydro-test methodology for Above ground laid 18" NB natural gas pipe line.

    The Pipe line is laid above ground and having 5 Nos of vertical thermal expansion loops.Client has accepted for the proposal in principle to carryout hydro-test on the line with visual examination for leakages of welds /pipe line in-lieu of underground hydro-test procedure . As discussed in...
  10. pdprao

    Hydro-test methodology for Above ground laid 18" NB natural gas pipe line.

    Thanks for your reply Mr BigInch. If the weld joints and full Pipe line is 100% accessible for visual examination during hydro test, why one need to adopt indirect method of water-loss assessment( by Pressure drop) with various corrections as applicable for underground pipe line? . If we are...
  11. pdprao

    Hydro-test methodology for Above ground laid 18" NB natural gas pipe line.

    What is the hydro-test methodology for Natural gas pipe line with test pressure of 74 bar which is laid above ground of 800 m length . The line is designed as per ASME 31.8 and being tested separately. a) Whether Underground pipe line hydro test procedures as per API- 1110 which is based on...
  12. pdprao

    painting of coolig tower structures

    which is better paint system for cooling tower steel structures. Is it inorganic zinc silicate with two coats of high build epoxy with total DFT of 250 microns OR polyurethene 100% solids with DFT of say 600 microns. which is better system out of the above two systems when applied with SA2...
  13. pdprao

    inclined plate settler

    we need to install Inclined plate settler IPS, for make-up water pretreament for cooling tower with IPS claifier. The capacity is about 125cum\hr with output tubidity level less than 10 NTU with input level of 100 NTU. I am intrested to know , how to finalise the detention time for IPS...
  14. pdprao

    CO2 MIG WELDING

    Mr BillPSU, Thanks for your feedback. You are exactly right in your comments. The contractor wants to go for CO2 MIG for economic reason. I fully agree with u co2 mig has many variables which can affect the quality. The joints are be subjected to U.T/ radiography. As such the quality...
  15. pdprao

    pipe suuports fabrication

    Quark , This is with reference to your comments regarding Indian standard ref. in my thread. The relevant I.S. is I.S.Sructural engineering hand book S.P(6)2, and S.P(6)3 which gives typ. welding details of box sections made from I.S channels

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