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  • Users: marklobo
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  1. marklobo

    Valve Flange Face Parallelism Standard

    Does anyone know of a published standard for straight-pattern valve body flange face parallelism? When flanges are welded to a butt weld glove valve body, there is no assurance of inherent parallelism as there would be if the facings were machined on a cast or forged body. I've been to the...
  2. marklobo

    Weld-fabricated Valve Material

    Would a 5000 psi rated valve fabricated from a butt-weld body of 75K material and weld-neck flanges require the flanges to be 60K or 75K material? According to API 6A -19th edition Table 4, a flanged “Integral end connection” must by of 60K or 75K material, though butt-weld 5000 psi flanges are...
  3. marklobo

    Can forged bar be used to make a forged valve?

    A section of forged bar per ASTM A350 LF2 is used to make a valve body. I was told by a forging supplier that the body could not be claimed to be a forging. OK, but then if the valve body is marked "A350 LF2", would that not imply it was made from a forging, since A350 is by nature a forging...
  4. marklobo

    Erosion and Corrosion Effect on Wear Parts

    What does this body of knowledge have about material choices for resisting erosion damage from fluids that are also corrosive? Since erosion resistance typically has an inverse relationship to corrosion resistance, would a Rc 55 low alloy steel (e.g. Nitralloy 135) suffer from corrosion to the...
  5. marklobo

    Flange Face Parallelism Standard

    Does anyone know of industry standards addressing parallelism of flange faces prior to installation? We have experienced a cracked fillet weld at the socket connection of a short lap-joint flange hub into a rigid pressure vessel. During installation, as the raised faces (piping flange and hub)...
  6. marklobo

    A105 and A350 Raw Material

    Could someone please enlighten me how a mill could certify that a material in bar form complies with a forging specification? I've been trying to get a straight answer from our material suppliers, and am not satisfied with what I've been fed. Does ASTM A 961 have the answer? If a manufacturer...
  7. marklobo

    API 6A and ASME B16.34 Ratings and Marking

    If a valve design is to be applied in either of two services (industrial or well head), with the difference being the approved materials, does marking imply compliance with the applicable specifications? For example, CL1500 A696 valve implies B16.34, whereas 5000 MOP API 75K implies API 6A. Is...
  8. marklobo

    BPD Steam to Mass Flow

    What is the method for converting steam volume flow rate in barrels per day (BPD) to mass flow rate, given steam quality, pressure and temperature?
  9. marklobo

    Pipe Ratings

    If a piece of hot-finished, seamless pipe (per ASTM A530) measures on the low side of OD tolerance (-1/32" under nominal), and the surface texture is required to be "cleaned-up" to 64 AARH and the pipe ends up .010" undersize, is it, therefore, non-compliant? If so, how does...
  10. marklobo

    Socket Weld Requirements per B31.3

    We regularly employ socket weld-type joints in fabricated piping components, and attempt to comply with ASME B31.3-1999, paragraph 328.5.2, and specifically, Figure 328.5.2C. I have trouble with the use of the word "approximate" in any specification, and in this case, the word causes...
  11. marklobo

    Fastener torque

    I'm looking for a compilation of fastener torque vs. size drive type vs. material. One of the "old-timers" remembers seeing a wall chart produced by a fastener company, but he doesn't remember the source. Specifically, my question is "what is the expected range of torque that a...

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