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  1. gibsi1

    External hydrostatic test pressure for "hot tap"

    Lots of emergencies require multiple signatures. You cannot sign off in advance. We can certainly have example calcs ready for use with each package, and for that FE would be great. I think that is the best path forward to re-write this entire procedure. It will take a bit of work to model...
  2. gibsi1

    External hydrostatic test pressure for "hot tap"

    I realize that it can't be considered flat and agree that accuracy is not very high. However, elevated safety factor is desired in these scenarios and the procedures are a worst-case guidline. Working from the extremely conservative flat plat calculation is a good thing. If it passes the flat...
  3. gibsi1

    External hydrostatic test pressure for "hot tap"

    I agree that you can't use the same calculation as when an entire pipe is exposed to the same external pressure. The value in all of this is preventing catastrophic failure that could lead to a release or expose water into a system where it shouldn't be. Some of these hot taps are done on...
  4. gibsi1

    External hydrostatic test pressure for "hot tap"

    Upon review of our internal procedure covering "hot tap" connections and associated testing, I've found a lot of discrepancy on acceptable calculation methods to determine appropriate external hydro test pressure and the required wall thickness to support it. We often perform "hot tap style"...
  5. gibsi1

    ASTM material cross reference

    I figured it wouldn't be easy! Thanks for all of the feeback.
  6. gibsi1

    ASTM material cross reference

    I've reviewed ASTM 00.01 Book of Standards, but it doesn't accomplish what I need. Some non-technical folks are assembling financial documentation that is based on original installation costs for various equipment, piping, etc. A lot of the original construction pieces lack sufficient...
  7. gibsi1

    ASTM material cross reference

    I am paid up with an electronic database through our company. I'm just not sure what the document(s) is titled/numbered. I need that to find it through the database. Searching by description is too vague and turns up hundreds of results.
  8. gibsi1

    ASTM material cross reference

    Is there any document(s) that lists each ASTM material number and defines the associated metallurgical content, intended use, manufacturing methods, etc? I've found a few nice websites here and there, but figured ASTM would likely have a document.
  9. gibsi1

    Valves as restrictive orifices

    Reducing the impeller costs us a lot of flow. This pump is in a very "utilitarian" sump application that doesn't need to be exact, but we do need to maintain good flow.
  10. gibsi1

    Valves as restrictive orifices

    I really don't want to do it, either. Others in the organization were bringing it up and I wanted to ensure I was correct in my stance to use an orifice plate. It would take a small valve and cumbersome amount of fittings to make the valve work. What is the correlation between orifice plate...
  11. gibsi1

    Valves as restrictive orifices

    Can you successfully use a reduced size and/or port valve in place of a restrictive orifice plate? I have an 1.5" sump pump discharge line that is much shorter and of less elevation than originally designed for. The change has caused the pump to operate way off the right side of the curve. I...
  12. gibsi1

    STANDARDS: Cast iron pipe replacement in sanitary service

    Thanks for the quick response! I can find some historical reference to A112.5.1, including the 1985 Alabama Builders Code, but nothing up to date. All recent documentation from Industry Standards and manufacturers seems to always reference ASTM A74, then the accompanying AWWA C110 and/or ANSI...
  13. gibsi1

    STANDARDS: Cast iron pipe replacement in sanitary service

    Does ANSI A112.5.1 still exist? I'm having a hard time find anything recent. What I do find from ANSI pertaining to ductile iron piping and fittings is A21.10 and accompanying documents. Our old plant spec requires materials to conform to ASTM A74 and AWWA C110. Researching C110 often labels it...
  14. gibsi1

    Freeze Prevention

    Hmm... wish you could edit your own posts. Why does the 3E software result in larger diameter pipe requiring more flow? Wouldn't the exact opposite be true because the large pipe has more volume and more heat to give up during transfer?
  15. gibsi1

    Freeze Prevention

    ...days that we'll be needing this? I also just noticed that I was using the wrong number of hours. I guess what I'm figuring is the worst-case scenario, which is 0*F and 20mph+ winds, so I would need to calculate it on a yearly basis (8760hrs) to find the flow needed for that case. Is this correct?
  16. gibsi1

    Freeze Prevention

    ...this for 4 months out of the year (1440hrs). I don't see how you are coming up with those 3E numbers. The cooling water supply runs at 65*F in the winter. We obviously need the water above freezing when it exits the pipe, so we'll use 35*F for the exit temperature. That gives an average...
  17. gibsi1

    Freeze Prevention

    The 3E software does not take the temperature of the resupply water into account, which is why the numbers are so much lower. Using lower process temperatures results in less flow required because 3E is assuming you want to maintain that temperature.
  18. gibsi1

    Freeze Prevention

    The water temperatures I am using are downstream of the pumps. We are talking enormous systems with multiple pumps putting out 5750GPM... each!
  19. gibsi1

    Freeze Prevention

    Well, the calculated results are vastly different. The Thermomegatech formula gives 95GPM for 65*F resupply water and 291GPM for 40*F resupply water. The 3E software and listed HVAC "formula" gives 27GPM. Not really sure where the problem is. I would've assumed the 3E numbers to be higher...
  20. gibsi1

    Freeze Prevention

    ...calculation software and formulas at www.thermomegatech.com, which they use to size freeze protection valves. For future reference... GPM = [A1*A2*(0.5*Tw-Ta+16)]/[40.1*d^2*(Tw-32)] GPM = gallons per minute of water flow A1 = Transverse internal area of pipe, ft^2 (Crane410, Navco, etc) A2...

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