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  1. Chumpes

    Cavitation Erosion Particle Size

    hello you dont need abrasion with solid particles to activate erosion. erosion can occur even with full liquid or full gas systems. maybe the pressure at inlet is so low that bubbles forms and promote cavitation. cavitation increases the average fluid velocity and promote impact-related damage...
  2. Chumpes

    Difference between ASME SA187 Gr.5 and ASME SA336 Gr.5

    hello why would you want these grades to be identical ? regards
  3. Chumpes

    alternatives to 321/347

    Ni-Alloy 625 is stabilized by Nobium addition and it will be able to withstand Tdesign 1250F as per ASME BPVC code.
  4. Chumpes

    Secondary Reformer Refractory Damage

    hello what type of anchors were implemented ? what were the results of mechanical testing (cold crushing test, PLC, ...) of this refractory on production mockup ? regards
  5. Chumpes

    SS 316L vs. EtOH-H2O 90-10 with 65ppm H2SO4, low O2, low Chloride @170°C

    Thanks Ed for this fast reply. I was wondering if the very low O2 levels may allow operation with a very few ppm chloride at high temperature (170°C) without acid. No additionnal oxydative contaminants are foreseen. Agreed O2 and oxydants would help SS resisting H2SO4 by promoting the building...
  6. Chumpes

    SS 316L vs. EtOH-H2O 90-10 with 65ppm H2SO4, low O2, low Chloride @170°C

    Dear all i have to select metallurgy for the following service : - EtOH-H2O (90-10%) full liquid at 30bar, 170°C. - low chloride content below 2.5ppm - low oxygen as the system is deaerated at Tamb under ppO2=1.25mbar - presence of 65ppm H2SO4, which would correspond to pH=2.9 in pure water. We...
  7. Chumpes

    NACE SP0472 Amine Service PWHT holding time and temperature

    Dear all, In order to inform you about the conclusion on this topic : A new repair procedure that respects NACE SP 0472 for repair's PWHT was proposed: defects identified are localized in the outer or in the inner half thickness section, and repairs from the outside or from the inside will...
  8. Chumpes

    NACE SP0472 Amine Service PWHT holding time and temperature

    Dear all, @0707 (Luis): thanks for your comprehensive explanation @Dhurjati Sen : thanks for the suggestion of multiple PWHT >> I am discussing the possibility of performing multiple short PWHT layer by bayer for better mechanical properties of the weld, i will let you know Still, multiple...
  9. Chumpes

    How do Aqueous corrosion and high temperature oxidation/sulfidation differ?

    even not getting into details, temperature remains an important parameter... HT corrosion mechanisms does not initiate below 200°C Another important parameter is the actual metallurgy... carbon steel ? SO2 + H2O can be very corrosive (acid dew point corrosion, wet acid corrosion, etc.)
  10. Chumpes

    NACE SP0472 Amine Service PWHT holding time and temperature

    Thanks for your answers @Sjones Well yes, ASME does not consider corrosion damage, but NACE does not consider much mechanical resistance either, excepted that(extract from NACE): "PWHT procedures as described in 3.4 and 3.5 can negatively affect the tensile strength and impact toughness of the...
  11. Chumpes

    NACE SP0472 Amine Service PWHT holding time and temperature

    Dear all, i could not find the answer to my question in other threads in the forum, that's why i have to ask you the following question... ASME PWHT of CS (P-No 1) with thickness above 125mm as per ASME VIII div. 1 (table UCS-56-1) asks for 2 hr plus 15 min for each additional inch(25 mm) over...
  12. Chumpes

    Damage mechanism for CI Piping used in NH3 and CO2 Service

    I guess this is full vapour system : in absence of chloride ions (or HCl) you can investigate the selection of SS 316L.
  13. Chumpes

    What causes steel plate opens up like a book?

    hello Damianyu I mean that it is normal to experience corrosion because carbon steel material will corrode when exposed to free water that dissolves oxygen : the painting system has to remain in good condition (repair of the painting may be required time to time) otherwise CS will corrode. in...
  14. Chumpes

    What causes steel plate opens up like a book?

    It could be corrosion by water containing oxygen of a plate (oriented material) of which the lining went off =)
  15. Chumpes

    Galvanic Corrosion and Electrolyte in piping

    Hello For your information, another common word that may replace the term "electrolyte" is "water". Free water (liquid phase) is the most common electrolyte that one can meet. Regards
  16. Chumpes

    Rated MDMT

    Hello the MDMT is the Minimum Design Metal Temperature, which definition is the minimum (cold) temperature at which a pressure equipment will be pressurized at pressure levels comparable to design pressure (we use 25% of design pressure). The MDMT is a process parameter, not a material's...
  17. Chumpes

    NACE TM0177 METHOD B TEST

    Hello methods A, B, etc. in ASTM TM 0177 are related to the loading type : method B is the "bent beam" method that differs from "method A, tensile". please have a look in the document you make reference to (NACE TM 0177) regards
  18. Chumpes

    Chloride Limits for Short Term Operation - SS347 & SS316

    hello PS6788 temperature 200F is kind of low temperature in the effluent of hydroprocessing units, and washing water injection was located here in order to dissolve (or to avoid formation in case of continuous wash water injection) of NH4HS solid salts that could condense at temperature lower...
  19. Chumpes

    NACE SP 0170 : Definition of wrought products

    thanks, i appreciate your answer as I am not a native english speaker =) ++
  20. Chumpes

    NACE SP 0170 : Definition of wrought products

    Dear all, NACE SP 0170 states : 6.2 Industry experience indicates that low-carbon or chemically stabilized austenitic stainless steel weld overlays and chemically stabilized austenitic stainless steel wrought internals in reactors operating at temperatures less than 455 °C (850 °F) are resistant...
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