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  1. dbevil

    Guidance Regarding Liquid Holdup

    You need to look at the difference between the slip and non-slip liquid. The difference is the volume of liquid that would be removed if you pigged the line. Also, if you did not include every elevation change greater than the OD of the pipe, the program will not give you an accurate liquid...
  2. dbevil

    Stress analysis of cross country piping

    Cross-country pipelines rarely require a formal stress analysis with programs such as Caesar. An above-ground fuel gas line may be designed as restrained or unrestrained. For either the design should consider the extremes of ambient and operating temperatures. Design and hydrotest pressures also...
  3. dbevil

    Guidance Regarding Liquid Holdup

    The effects of liquid holdup will be the result of a number of factors and is very complex in nature. The ratio of liquid to gas is an important factor as well as the relative densities of the two phases, as well as the mixture velocity. Another important factor is the inclination of the pipe...
  4. dbevil

    Single Phase Pipe sizing criteria

    With considerable experience in the subject of erosional velocities, I offer the following memo drafted to address the subject as pertains to an ammonia pipeline: Many companies, have in their process piping go-bys or rules-of-thumb, references to a maximum velocity of fluids in piping. This...
  5. dbevil

    MEASURING TWO PHASE FLOW

    There is not any in-line instrumentation capable of accurately measuring two-phase flow of any sort, that I am aware of. In the process of designing 80 km of steam pipeline, my solution has been to measure the vapor phase at the destination (in this case, 250 injection wells) and subtract it...
  6. dbevil

    Wave Speed in Liquid Ammonia

    25362: The higher pressure system I spoke of was also at higher temperatures as well, since ammonia is liquid at those conditions. Your right for -28°F but the wave speed does go down for higher temperatures. This chart, however, does give much higher wave speeds even at higher temperatures...
  7. dbevil

    Wave Speed in Liquid Ammonia

    Thanks to all who have contributed here. I now have the info I need to complete my calculations. I had found a value at another location listing 4900 ft/sec, but didn't think it was accurate, since that's higher than water! The wave speed is a measure of the compressibility of a fluid and I was...
  8. dbevil

    Wave Speed in Liquid Ammonia

    I'm again in the process of doing surge studies. This time on an anhydrous liquid ammonia line (-28°F., ~50 psig). I can't seem to find a source for the wave speed (acoustic velocity) of liquid ammonia nor can I find the bulk modulus for ammonia. Can anyone point me to a reference for either of...
  9. dbevil

    Slurry and Two Phase flow

    The University of Kentucky civil and mechanical engineering department has developed comprehensive and inexpensive hydraulic programs dealing with slurry and network flow as well as transient flow (surge analysis). They offer regularly scheduled training sessions and siminars on the use of the...
  10. dbevil

    Line pipe grade and schedule identification

    These methods will tell what what the composition of the material is, but won't tell you what grade it is. The process of manufacture also affects the strength of materials, such as cold-working and other techniques. The only way to test the strength of materials is in destructive tensile and...
  11. dbevil

    AMMONIA LINE

    AMSE B31.3 should only be used if the line is totally conatained within the boundaries of of single plant. If the line is cross-country and/or crosses public lands or roads, then the provisions of ASME B31.8 and CFR Part 192 will apply. But I agree that any line over 2" should be butt-welded.
  12. dbevil

    Software to analyze the transients of a steam pipeline

    Tremolo, No, I have not found a suitable commercial package. I have started on a spreadsheet, but think it's going to take something more powerful. I have steam functions for a spreadsheet, but not for a BASIC program.
  13. dbevil

    2-phase flow thro' orifice: any comments?

    For what it's worth, most two-phase flow calculations thru orifices are only accurate if the two phases are in one of the homogeneous flow regimes (i.e., mist flow or distributed bubble) thru the orifice. For all the other flow regimes (stratified, wavy, annular, plug, or slug flow)two-phase...
  14. dbevil

    Molten Sulfur physical properties

    There is a lot of data here for the physical properties of sulphur: http://www.webelements.com/webelements/elements/text/S/phys.html
  15. dbevil

    Liquified propane piping materials

    We use normal carbon steel for all liquid propane service. The charpy requirements for steel are based on its strength under full pressure. If you depressure the pipe to get it cold, there is no load on the pipe and thus, there are no strength or charpy requirements. Just don't strike the cold...
  16. dbevil

    Software to analyze the transients of a steam pipeline

    Kann, During a cold start, there will obviously be more "drips" than a few a kilometer. Before steady state is achieved, about 2000 cubic meters of condensate will be formed. In this system, there is no need to remove 100% of the condensate formed during startup, since the ultimate...
  17. dbevil

    Friction Factor of Stainless Tube

    Be careful not to design too close. A roughness of .000005 in. would not give a significantly different answer than using smooth pipe.. As a worst case, consider a higher value to account for aging, deterioration of the surface, debris, jointing method, etc.
  18. dbevil

    transients pressures with compressible gases

    I researched this at length many years ago and the conclusion then was that the increase in pressure due to a sudden stoppage of gas was so small that it was not really within the accuracy of the hydraulic gradient calculation to begin with. At extremely high pressures and low temperatures, it...
  19. dbevil

    Pipe Insulation Specification Using Ceramic Fiber Insulatiuon

    There are quite a few vendors who can assist with this. Search the web for "ceramic fiber insulation". I have the number handy for LandCoast: 800 367-5982.
  20. dbevil

    Vent and drains in Hydorgen cross country pipe lines

    There are quite a few hydrogen pipelines running around SE Texas and S. Louisiana. All such pipelines must conform to U.S. D.O.T.'s Pipeline Safety Regulations Part 192 - Transportation of Natural and Other Gases by Pipeline (unless the lines are totally contained within private property, i.e...
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