Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Search results for query: *

  1. YuJie_PV

    An ASME interpretation regarding UW-11(a)(5)(-b)

    i am reading Interpretation "BPV VIII-1-19-11", and encounter a problem: Background: A vessel has a 14" NPS nozzle which is 15mm (0.59") thick with a Category C butt weld between the nozzle neck and a flange. The nominal thickness at the welded joint does not exceed the thickness in UW-11(a)(2)...
  2. YuJie_PV

    the reason of the change with UW-11(a)(4)?

    i accidentally find one change of UW-11(a)(4) in ASME VIII-1 since 2019 edition. UW-11(a)(4) of 2017 edition: (4) all butt welds in nozzles, communicating chambers, etc., with the nominal thickness at the welded joint that exceeds the thickness in (2) above or attached to the shell or heads of...
  3. YuJie_PV

    MOC for a tower with MDMT -70C ?

    Thanks Geoff, i am the designated agent of owner now, i just think using lowest recorded temperature as MDMT is overconservative. Thanks
  4. YuJie_PV

    MOC for a tower with MDMT -70C ?

    thank you all. Geoff, -70C MDMT is due to service, instead of min. atmospheric temperature . BTW,i'd like to deviate a little from the original question, if i may. you mentioned the -40/-45C MDMT in northern Canada. i guess it's based on atmospheric temperature. i wonder what atmospheric...
  5. YuJie_PV

    MOC for a tower with MDMT -70C ?

    hi, all i've a question regarding MOC of a tower, which is constructed to ASME VIII-1 it's a deethanization tower with diamter of 2.5m, and height of about 50m,Design pressure 4.6MPa, Design Temp 150C, MDMT-70C. i would like to fabricate the tower with a low alloy material. i don't like to use...
  6. YuJie_PV

    is such practice for fatigue analysis normal?

    @geesaman.d . yeah. the cannon is stated to be constructed to ASME Code. i concur with your opinion, just the issue lies in how to demonstrate that. if i get the vendor's some oral promise and let it go, it seems ridiculous. Thanks.
  7. YuJie_PV

    is such practice for fatigue analysis normal?

    Thanks @IdanPV, i know the screening option based on 'experience with comparable equipment'. if i choose this option, there are so many hoops to be jumped through. is there any guidance? For example, i've ever read TSG4's statement on what constitutes 'sufficient time'. "if you can demonstrate...
  8. YuJie_PV

    is such practice for fatigue analysis normal?

    hi all, i come across an issue regarding how to exempt the fatigue analysis for the air cannons. the situation is such that i am working with an equipment to which several air cannons are attached. the cannons are used to prevent accumulation of powder in the filter. the air cannons are just...
  9. YuJie_PV

    is RT/UT available to angle joint?

    @r6155, the engineer is not qualified personnel of NDE, but a mechanical engineer doing a lot of shop inspection in behalf of owner, and similar work. my design details shown as below. and the diameter of small end is 1200mm, large end 2000mm. half apex 60degree. thanks
  10. YuJie_PV

    hot dip galvanized bolts forbidden on Stainless Steel vessel?

    @SJones, @Louisiana Inspector,@GGedge, @ProSafPlant1 Thanks for all your replies. there is something really broadening one's horizons. @ProSafPlant1, thanks for your PPT, i am reading it, it's very inspiring. you mention Flixborough disaster as well in the summary. regarding the disaster, i...
  11. YuJie_PV

    is RT/UT available to angle joint?

    @R6155, thanks for the reply. the engineer with whom i consult states the RT could be achieved even the half apex is 60 degree. you just mentioned "impossible in some designs", is it referring to the half apex also? Thanks in advance.
  12. YuJie_PV

    is RT/UT available to angle joint?

    @Heaviside,SnTMan, thank you both for your reply. SnTMan, i think you hit nail on the head. Thanks.
  13. YuJie_PV

    is RT/UT available to angle joint?

    @weldstan,heaviside1925, thanks for your reply. i am familiar with what NA stands for. i am just wondering why NA is specified for angle joint while RT could be atually performed. thanks
  14. YuJie_PV

    is RT/UT available to angle joint?

    Hi all, it's regarding NDE of angle joint defined in ASME VIII-1. angle joint is indicated as NA in table UW-12 regarding NDE, but i checked with engineer experienced in NDE, and find RT, and UT could be performed for angle joint in case that the diameter is large enough. i am confused now...
  15. YuJie_PV

    hot dip galvanized bolts forbidden on Stainless Steel vessel?

    @SJones, never heard of that before. if it's true, there seems a large misconception widespread in the industry. my spec states as follows: "As a reminder, due to low friction property of PTFE coating, in certain cases, PTFE coated bolts and nuts show self-loosing characteristic, and this...
  16. YuJie_PV

    hot dip galvanized bolts forbidden on Stainless Steel vessel?

    @SJ, it's from the project specification, and my colleagues also believe that.
  17. YuJie_PV

    hot dip galvanized bolts forbidden on Stainless Steel vessel?

    @Louisiana Inspector, there are some vessels subject to pressure fluctuation in the project. it's said that PTFE-coated fasteners are prone to loose themselves in case of vibration. thanks
  18. YuJie_PV

    hot dip galvanized bolts forbidden on Stainless Steel vessel?

    @SJones, never heard of the coating before. it seems impossible to be economical. Thanks
  19. YuJie_PV

    hot dip galvanized bolts forbidden on Stainless Steel vessel?

    @TugboatEng, thanks. Actually, Dacromet is mainly comprises of Zinc flakes. For my project, the engineers have agreed to abandon the idea of universally forbidding HDP regardless of the specific conditions of each equipment after discussion. Thanks
  20. YuJie_PV

    hot dip galvanized bolts forbidden on Stainless Steel vessel?

    @SJones, @Ed, thanks for your points. I agree that zinc could potentially cause LME failure. If galvanization is ruled out, it's hard to find an alternative that is both economical and obtainable, especially in highly corrosive atmospheres. It's a tradeoff, I think. thanks
Back
Top