Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: Rubje
  • Order by date
  1. Rubje

    CSB Final Report - YENKIN LP Pressure Vessel explosion - ONE DEAD, Massive Damage

    @georgeverghese In response to your last comment c, it seems they should had stayed at the original design pressure of 40 psig since cleary it reached 15 psig quite often. This is just speculation but it seems they "derated" the vessel to 15 psig in order to get out of doing the API 510...
  2. Rubje

    Wrong Tensile Strength on 2 different U1A

    Hi all, A client of mine has two ASME VIII stamped pressure vessels made by different companies in the 60s. Both are made of SA-7 and what puzzles me is the Tensile Strength on each vessel is 55k but the code says there is a 0.92 quality factor thus giving an allowable stress of 12,650 psig...
  3. Rubje

    API-ASME: 579: General vs Local Corrosion

    579 doesn't draw a clear distinction between general(part 4) and local corrosion (part 5) Any guidance on how I can determine which part (4 or 5) to use depending on the situation? thank you
  4. Rubje

    Have you ever seen a 3:1 ellipsoidal head used on a vessel?

    @Ariba01123 Thank you for sharing that reference. Do you know the difference between sigma 1 and sigma 2 is in the photo? Interesting that above 1.42 for a/b, the hoop stress becomes compressive near the knuckle and crown region (and above 2 the compressive is greater than the tensile stresses).
  5. Rubje

    Have you ever seen a 3:1 ellipsoidal head used on a vessel?

    Thanks everyone for the responses! MJCronin, my reference is ASME VIII Div. 1. They give different k factors for ellipsoidal heads. A 2:1 has a k factor of 1. Also, why does Pharma use that 80-10 head?
  6. Rubje

    SS 321H Material Welding Joints PWHT Necessity

    @sahsanb "Root cause of Stress Relaxation Cracking was identified to be non-compliance to WPS (high heat input) at the time of original construction ( i.e. year 2010)" Did the damage mechanism start shortly after the equipment was installed?
  7. Rubje

    Have you ever seen a 3:1 ellipsoidal head used on a vessel?

    I only seen the standard 2:1 ellipsoidal head used on vessels and I'm curious if anyone seen any other ratio used before. If so, what was the reason why that particular ratio was used and not 2:1?
  8. Rubje

    Design Margin of Pressure Vessle

    @DriveMeNuts "For ASME materials, the guaranteed minimum Yield and UTS of a material which is mandatory in design calcs, corresponds to plate which is ~100mm thick. However, 20mm plate has material properties superior to 100mm plate, and therefore there is waste material in 20mm thick vessels...
  9. Rubje

    Material Brittle Transition Curve - Cert vs Client

    Is this for piping, vessel, tank? If so those ASME codes associated with those equipment have criteria regarding impact testing.
  10. Rubje

    Pressure Control in two-stage refrigeration system

    That makes sense. thanks Do you know where i can find an SOP for an industrial refrigeration process? I found documents online that describe the system but I really want to learn more about the controls and how engineers change the various process variables.
  11. Rubje

    Liquid Nitrogen to Cool Condenser Water

    @Edstainless What are the name of these exchangers? Haven't heard of them but sounds neat!
  12. Rubje

    Auto-Variable Pitch for Air coolers Control

    I don't have experience with it but I heard from some air cooler vendors that they are hard to maintain and the pitches don't always match the set points. Any consideration in using VFDs to control air flow? Those are pretty standard.
  13. Rubje

    Pressure Control in two-stage refrigeration system

    Thank you for the response. So hypothetically, what would happen if the outlet pressure from stage 2 is pushed based the vapor pressure? Would the vapor simply condense? Would the outlet temperature from the condenser simply increase to match the new discharge pressure? I imagine it's hard to...
  14. Rubje

    Pressure Control in two-stage refrigeration system

    "You can also increase throughput if there is some extra cooling capacity at the stage 2D fin fan condensor, since this will in turn result in less flash gas generation at the economiser flash tank which floats on stage 2S." But the 2nd stage discharge pressure would still be limited by...
  15. Rubje

    316SS vs 304SS pump for RO water application

    @TugBoatEng "The Mo in 316 is primarily added for chloride resistance. Your fluid has very little chloride so I see no benefits to running 316." I don't believe that is true. I read studies that 316 still offers better corrosion protection for non-chloride containing environments compared to...
  16. Rubje

    Piping Considerations for Pipeline with Sand Erosion

    I read each comment in this post. Thank you everyone this was super helpful
  17. Rubje

    Piping Considerations for Pipeline with Sand Erosion

    I'm working with a client that is dealing with high erosion rates due to sand in the well. I'm brainstorming some piping changes that can be made to decrease to erosion rates. Here they are: -Avoid 90 elbows and rely on 45 elbows -Size piping to have a flow velocity less than 10 m/s -Avoid...
  18. Rubje

    ASME VIII 1943 Sections U-68 and U-69

    Why were there two separate codes back then? How did one know which one to use back then? From what I read, if a vessel was built to API-ASME it didn't have a U stamp correct?
  19. Rubje

    ASME VIII 1943 Sections U-68 and U-69

    @weldstan True and rightfully so due to the technology back then However, the S.F. was increased to 4 temporarily due to WWII in the early 40s to save metal for the military. Is it safe to assume that any vessel built during this time period should be heavily questioned if they are still in...
  20. Rubje

    ASME VIII 1943 Sections U-68 and U-69

    @Christine74 Thank you for the guidance. Do you know why the joint efficiencies were relatively high in the 40s but were lowered starting in the 50s? I find that concerning because many of these old vessels were built with very little corrosion allowance so if today's joint efficiencies were...

Part and Inventory Search

Back
Top