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  1. zabrab

    StormCAD - Modeling Gutter and Conduit Flow

    I'm not sure I understand the actual situation you are trying to model, but 56 cfs would be an excessive flow to capture with an inlet or two and may not be able to be safely conveyed within your roadway section to actually reach the inlets. That being said, how do you have the catch basin...
  2. zabrab

    Looking for a particular stream restoration detail (grade control)

    I haven't seen them in a while, but I know them as a "log drop structures" or a "log weirs."
  3. zabrab

    Upsizing storm pipe to increase velocity

    Drew08, I was looking at the conditions at a given flow rate, not the maximum capacity of the pipe. Point taken, I was comparing the 15" that I arbitrarily set as flowing full as that was implied in the OP, but I did not impose any type of constraint on the larger diameters. However, depth for...
  4. zabrab

    Upsizing storm pipe to increase velocity

    I ran some calculations by hand at lunch and then realized I could use a program we have, Bentley Flowmaster, to run the numbers. Right from the start the results did not match my calculations. Long story short – don’t use the hydraulic elements graph in the Wisconsin DOT Facilities Development...
  5. zabrab

    Upsizing storm pipe to increase velocity

    My initial reaction was to generally agree with the prior responses, but after thinking about it for a moment, I am not so sure. There are conditions under which upsizing a pipe would increase the velocity. I’ll have to pull a book and bang out some numbers to verify. I’m assuming constant Q...
  6. zabrab

    Need flow rate calculation for telescoping valve

    If you cannot get a flowchart from the manufacturer, you can estimate flow as a weir for low heads and an orifice for higher heads. E&S pond designers use a riser pipe for spillways. There is a good explanation in Section 13.6.10 (pg 41 in the link). It may give a procedure you can use...
  7. zabrab

    Flushing Water Mains - Scouring Velocity

    Minimum flushing velocity per AWWA C651 is 2.5 fps so 3.5 fps is a good target for public mains. There is a table in the standard that indicates flows needed for 2.5 fps and the size/number of taps needed at a pressure of 40 psi. For private fire mains, flushing velocities may potentially need...
  8. zabrab

    Very Basic Question on Testing Potable Water Lines

    Pennsylvania DEP just implemented a new policy that might be of use to you: Policy for Determining When Loss of Positive Pressure Situations in the Distribution System Require One-Hour Reporting to the Department and Issuing Tier 1 Public Notification It's 9 pages and the bulk of it deals with...
  9. zabrab

    Wet Stamp, Embossed Seal, or both

    In PA, technically, you have first have to obtain a seal and then you can obtain/use a stamp or computer version as these are "facsimiles" of your seal. Also according to the PA regs, the 1st plan sheet is supposed to be signed and sealed with facsimiles only used on subsequent plan sheets.
  10. zabrab

    Sign Post Deflection

    To expand on what bjb said, try AASHTO's Standard Specifications for Structural Supports for Highway Signs, Luminaries, and Traffic Signals.
  11. zabrab

    Inlet scour protection

    lpseifert, My experience is that "splashing" is normally not an issue with concrete inlets. What is unusual about the configuration on the incoming sewers that precludes the use of the standard inlet box for your locale?
  12. zabrab

    Asphalt Surface Variations

    Assuming the paving operations did not occur over a base with abrupt vertical transitions, vertical differences due to compaction of areas of deeper lifts should be somewhat gradual and would have more of an “undulating” ride, something that would be noticeable on a high-speed roadway. “Bumpy”...
  13. zabrab

    mechanical joints vs flanged

    Fel3, I’m located in southeastern Pennsylvania. I have used flanged fittings underground, but their use has been limited to very specific instances. When bringing a line up into or down out of a pump house, my early designs had the underground vertical-to-horizontal bend rodded up to the...
  14. zabrab

    mechanical joints vs flanged

    fed3, You are correct for a tapping sleeve and valve. In my area a flanged joint would not be used between a standard tee and valve. In my area, it would be MJ tee, spool piece, MJ valve.
  15. zabrab

    mechanical joints vs flanged

    Flanged Joints are rigid, but are also restrained. They do not allow for any deflection which may come about due to minor misalignments and/or settlement which are common in underground installations. They are only used in aboveground installations. Mechanical Joints are flexible, but do not...
  16. zabrab

    Fixture Quantity, Septic Tank and Leach Field Sizing

    Yes there are standards, but, unfortunately, they are not standard; they vary from Jurisdiction to Jurisdiction. Here is a link to the standards here in Pennsylvania: http://www.pacode.com/secure/data/025/chapter73/025_0073.pdf Sewage flows are discussed in section 73.17, absorption area...
  17. zabrab

    rotating bends

    Most manuals from pipe manufacturers have formulae for computing the offsets. Here is a link to an online manual, refer to pg 17-26. It should be self-explanatory once you see it. http://www.acipco.com/adip/products/Sect17.pdf
  18. zabrab

    Utility Trench Settlement- acceptable tolerances

    If the accepted paving practice is 1/4", that is what I would follow. You should also be sure of what is considered the maximum dropoff from a traffic safety standpoint. If you are not going to follow a definitive 0", 1/4", 1/2" or whatever, observe the project after a rain. Any birdbaths or...
  19. zabrab

    Cross Slope across bottom of storm box?

    Many jursdictions in my area have a prescriptive requirement of 0.1 ft to 0.17 ft (2 in) when entering and exiting pipes are the same diameter and matching pipe crowns when the pipe diameter increases at a drainage structure.
  20. zabrab

    PVC SEWER SPECS

    From your question it sounds as if the sewer will be within the normal and customary water/sewer isolation distance established by the AHJ (authority having jurisdiction). If this cannot be avoided, there usually is a provision to construct the sewer with upgraded (pressure rated) pipe to lessen...

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