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  1. regular

    Correct Torque for Bolt Stress

    jte, Many thanks for the info. Will read up on the Garlock pdf.
  2. regular

    Correct Torque for Bolt Stress

    codeeng- / jte, Most of the response did not actually address in total my query. However, the discussions and materials that surfaced are informative nontheless. I think I have gleaned from the discussions, a rough answer to my query though I would have preferred if someone could give me a...
  3. regular

    Correct Torque for Bolt Stress

    Hi unclesyd, Your suggestion to use 20,000 + 2000 sounds logical and reasonable. But my main concern in the example given would be that if I had used the max. allowable bolt stress ( which appears to be the standard when referring to torque versus bolt stress charts), then wouldn't the gasket...
  4. regular

    Correct Torque for Bolt Stress

    Guys, Your response appreciated. But I think you may have missed my point viz. I noted in quite a few cases that the actual bolt stress (for each bolt of the flange) required for the design gasket seating ( or operational pressure) is much lower than the max. allowable stress used during...
  5. regular

    Correct Torque for Bolt Stress

    ASME V111 Div.1 Appendix 2 has provision for flange design and also bolt size and number based on the allowable bolt stress. I note that in most cases, the required bolt stress is low ( way below the allowable tensile stress allowed for the bolt; basically because of the large number of bolts...
  6. regular

    Stainless Steel Flanged Piping With Carbon Steel Bolts and Nuts

    Fizzhead / unclesyd, The past threads were really informative. Thanks Alas, someone who has experienced the sus bolts/nuts loosening. Because, I have not personally known of such incident though I have heard that it is a possibility. Then again, our pipes are not subjected to cyclic...
  7. regular

    Stainless Steel Flanged Piping With Carbon Steel Bolts and Nuts

    Guys, Thanks for the feedback. From the comments and advice, I have managed to get an idea. Dcasto's banding idea is interesting and I think I would like to consider that. My concern with wax is whether there is any risk of chloride contamination. Sure is worth looking into.
  8. regular

    Stainless Steel Flanged Piping With Carbon Steel Bolts and Nuts

    Guys, Thanks for the response. However, I need clarification viz. the pipe flanges are standard ANSI B16.5 sus flanges and the operating temperatures are low circa zero deg. C. I would have thought that the stainless steel bolts and nuts should be able to take the required stresses for proper...
  9. regular

    Stainless Steel Flanged Piping With Carbon Steel Bolts and Nuts

    Hi Prex, Problem with the carbon steel bolts/nuts is that the pipe is a cold service and we get condensation on the bolts/nuts (where insulation have failed) and as a result they get corroded. Need to clarify what you mean by stainless steel is less resistant than carbon steel. Regards
  10. regular

    Stainless Steel Flanged Piping With Carbon Steel Bolts and Nuts

    I note that in my plant, carbon steel ( B7 /H2 bolts and nuts are normally used for stainless steel ( 304/316) flanges. I understand that the reason for this is that stainless steel bolts and nuts are harder and the tendency for the nut to loosen is high, hence the use of carbon steel...
  11. regular

    ANSI Flange Pressure Ratings

    Morten A - thanks. The relief valve would be a quick acting type.
  12. regular

    ANSI Flange Pressure Ratings

    Guys, Thanks for the comments and advice. We are considering following steps viz. 1. Stop the pump at the same time the valve is to be shut. The timing of stopping needs to be fine tuned as the pipe run is rather long. This should prevent hammering. 2. The shut off valve is "air to...
  13. regular

    ANSI Flange Pressure Ratings

    ANSI B16.5 furnishes information on Pressure / Temperature ratings of flanges. The pressures given are for NON-SHOCK values. I have a pipe run (approx. 400 metres long) that occassionally experiences "hammering" due to rapid closing of a valve. Would appreciate if anyone can tell how I can...
  14. regular

    Allowable Longitudinal Compressive Stress - Heat Exchanger Design

    Thanks guys.
  15. regular

    Allowable Longitudinal Compressive Stress - Heat Exchanger Design

    TEMA design has provision to check the actual longitudinal stresses in the shell and tube (periphery of bundle) against allowable stresses (both tensile and compressive). The code provides a comprehensive guide to determine the allowable longitudinal compressive stress for tubes but mentions...
  16. regular

    P Group of A 543 Type B Class 1.

    I would like to know the P group for the high strength low alloy steel plate A 543 Type B Class 1. Understand that PWHT is not required for this group as per ASME V111 Div. 1
  17. regular

    ASME V111 Div.1 Weld Category /Type/Joint Description

    I did not read ExAI's response when I gave the example. But how does full radiography upgrade a joint that is welded from one side (and for which the root weld is definitely not as good as a double side welded one noting that the code accepts certain welding inadequacies or indications.) Also...
  18. regular

    ASME V111 Div.1 Weld Category /Type/Joint Description

    Thanks Prex. Consider the following situation: I have a Category B circumferential weld in a >24 inch diameter and > 5/8 in.thick that I can weld both sides but choose to do a type 3 joint albeit with a good TIG root run Does the code allow that ? And also what would the joint efficiencies...
  19. regular

    ASME V111 Div.1 Weld Category /Type/Joint Description

    Table UW-12 lists the Weld Type associated with Joint Description and Limitations. The limitations for Type 3 ( Single welded butt without backing strip)are: Circumferential butt joints only, not over 5/8 " thick and not over 24 in. OD. Does this mean that the code does not allow a vessel...

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