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  • Users: JHWC
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  1. JHWC

    Rail crack

    Hi Experts, Would like to seek your opinion on the rail crack (see attached). Please advise. 1. Is that consider a beach mark around the circular patch? To me, it seem more like an oxidation rather than beach mark. 2. Consider thermite welding was performed to this rail 7 years ago, how will...
  2. JHWC

    Grease applied to Motor Bearing.

    Hi Experts, May I ask for normal equipment (point machine in railway), what are the type of grease that can be applied to the motor bearing? Information: Equipment placed: Viaduct Temperature: Could be around 25 to 45 degree Environment: Normal/High vibration due to train passes Please...
  3. JHWC

    Determine the actual burnt of metal (Internally or Externally)

    Hi All Experts, Just a question, I am dealing with a burnt metal which is used in the track railway. Recently, there was a burnt on the metal, probably due to arc flash or arc blast. My questions are as follow: 1) Based on visual inspection, would we able to determine whether the burnt...
  4. JHWC

    Drilling of Hole + Tapered Screw Dimension

    Hi All, I have few questions pertaining to drilling, hole size and tapered screw thread. Please see the picture attached for clearer illustration. 1. If the diameter of my LUG is 21.5 mm, should the drilling size of the hole be bigger or smaller than 21.5? If it is bigger, at what...
  5. JHWC

    Railway Damaged - Cable and Rail Joint

    Hi Everyone, Would like to consult and seek everyone advise on the kind of damages and what could have causes it. Please see attached for more information. Several Observations: 1. There are total of 4 holes drilled onto the railweb for the power cable installation. I have name it A, B C...
  6. JHWC

    Poor Welding and the Colours formed on the surface

    Hi All, I have posted something similar under the section "material and metallurgy engineering", titled: Welding Issue. As far as concern, the comments were beneficial, stating that the welding was lacking of fusion and penetration (see attached). However, I have another concern. Does...
  7. JHWC

    Welding Issue?

    Hi All, Recently, two rectangle hollow bar which was welded together was detached from each other after years of operation. Kindly see attached. I would like to seek professional advise here on what could be the possible reasons for such failure? It seem to me this was probably due to poor...
  8. JHWC

    Bending or Torsional Fatigue?

    Hi All, Kindly see attached for the fracture surface of mild steel material. I am not sure is this fracture bending or torsional fatigue? Does anyone have any insight? Thanks...
  9. JHWC

    Stress Relief for zinc alloy and mild steel - Diecasting process

    Hi, Take a rectangular plate as an example. Can anyone please advise me whether zinc-alloy (96% zinc + 4% aluminium) and mild steel (AISI 1020) which are made from diecasting process are require to undergo stress-relief process? Is it logical to do this? Thanks.
  10. JHWC

    Could it be rust? Need help in identifying the type of corrosion.

    Hi, Please see picture attached. The picture shows the gate material (Stainless Steel AISI 410) coated with Tungsten Carbide. By right, we should not expect any corrosion or rust taking place. We try to touch the "rusting" part on the surface, but it was still smooth. Any comments...
  11. JHWC

    AISI 410 SS to withstand high contents of Chloride

    Hi All, For oil and gas equipment, Stainless steel is chosen (AISI 410). However, the customer stated the requirements; must be compatible with the following: (a) Water-based Mud (WBM) (b) Oil-based Mud (OBM) (c) Brine (KCl, CaCl2, CaBr2, ZnBrs) (d) Chlorides > 250 000 ppm (e) pH>9 (f) 15 -...
  12. JHWC

    PMT - Peak Metal Temperature

    Hi All, I have a question to ask everyone. When it comes to Xylan coating, there is this term called Peak Metal Temperature (PMT). For example, cure temperature 220 - 345C/20-5 min.. How do one interprete 20-5 min? I need help on this. Thanks, Jeffrey
  13. JHWC

    Additional test requirements and controls on case depth for NACE rated equipment

    Hi All, Does anyone know what are the additional test requirements and additional controls on case depth for NACE rated equipment? Thanks, Jeffrey
  14. JHWC

    Martensitic Stainless Steel - NACE - Impact Properties based on API 6A

    Hi All, I would like to ask what are the ways to find out which steels have poor impact properties. For example, AISI 410 material is a NACE SS material that have temperature rating of P, R,S,T and U under temperature classification in API 6A. On the other hand, S41500 or F6NM which is also...
  15. JHWC

    Tungsten Carbide/Molykote/Xylan Coating for the upstream equipment (Oil and Gas)

    Hi All, In my current company, we often recommend tungsten carbide, molykote and xylan coatings for upstream equipment. The reason for coating? Probably to increase the lifespan and the prevention of any corrosion. Often, I hear the word, "cycle" being used. I am curious. How do one...
  16. JHWC

    NACE - ISO 15156 - VERSION 3 - 2015

    Hi All, Many thanks for the help in advance. Truely appreciate all the reply. My question here goes: Since the latest version of ISO 15156 (Petroleum and Natural Gas Industries - Materials for use in H2S containing environments in oil and gas production), 3rd edition, has been released, I...
  17. JHWC

    Low Alloy Steel (AISI 4130) and Stainless Steel (AISI 410) in API 6A - Wellhead and Christmas Tree

    Hi All, I have doubts on the mechanical properties for material selection, especially on the low alloy and stainless steel which are often used in wellhead and christmas tree (API 6A) in oil and gas industries. Imagine on the following scenario: AISI 410 (martensitic stainless steel) for...
  18. JHWC

    Typical Value in Seal - HNBR

    Hi All, The team that I work with is require to buy a HNBR seal. The vendor has provided us with 1 catalogue with the test values given (attached). I am interested to know about the immersion test. I have downloaded the required ASTM (471 and 5964) for my references. 2 questions I want to...
  19. JHWC

    Phosphate coating for stainless steel

    Hi All, I would like to know the reason why phosphate coating is not suitable for stainless steel? Saw one of the posts stated that Cr contents above 5% is not suitable. In wiki, it stated high nickel contents. May I know why and how it affects the SS? Thanks for the guidances in advance...
  20. JHWC

    Elastomer: PTFE and PEEK

    Hi All, I would like to know which elastomer (in general) is better? PTFE or PEEK. It appears to me that PEEK cost more than PTFE, so I am assuming it should be a better material? May I also ask about the properties for PEEK in terms of (a) Sunlight (b) Oxidation (c) Gas Permeability & (d)...

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