45 or 90 elbow. Does it really matter?

Discussion in 'Equipment' started by Vhuang168, Feb 25, 2017.

  1. Vhuang168

    Vhuang168 Supporting Member

  2. roostertech

    roostertech reef noob

    I think at 1" pipe diameter, the difference won't be that visible. I'll be more interested in the same test for 3/4 and 1/2
     
  3. yellojello

    yellojello Supporting Member

    Read the comments. Looks like drain might have more of a difference because of air pockets?
     
  4. jonmos75

    jonmos75 Supporting Member

    There can be difference but not significant as a 45 degree reduces the flow of half what a 90 degree fitting does, yet you need (2) 45's so they almost become equal in flow loss.

    Here is a chart of flow restrictions based on pipe size and fittings
    http://www.engineeringtoolbox.com/pvc-pipes-equivalent-length-fittings-d_801.html

    The FMM with flow sensors has shown a lot of the NSI beta testers they did not have as much flow in their tank that the originally thought and plumping plays a big factor in reduction of flow.
     
  5. sfsuphysics

    sfsuphysics Supporting Member

    I wasn't a fan of how they did that test setup, two 45s next to each other that makes a gradual 90. Now whether or not that makes a difference is to be seen, but maybe they should have found a way to do that test with a single 45 vs a single 90 and see if there was any noticeable difference, then bump it up to 2 45s vs 1 90.
     
  6. rygh

    rygh Supporting Member

    Just over size the pipe a bit, and you can pretty much ignore all that nonsense.
    Larger pipe = lower velocity.
    lower velocity = less kinetic energy change at elbows, and less friction in the pipe.
    But not just by a little!
    Pipe volume is a function of the square of the diameter.
    Friction and kinetic energy is a function of the square of the velocity.

    So: Doubling a pipe from 3/4" to 1.5" pipe = 1/16 the losses.
     
    Julius Chen likes this.
  7. xcaret

    xcaret Supporting Member

    I've never put too much attention to the math involved in flow loss; ~5' of head loss when I had the tanks was not a crucial thing for me but If I had to be pumping a la CalAcademy style reef, then yes, lots of numbers to figure or for those of you guys who have a tank on the main floor, sump in garage or basement then I guess would be a pretty good issue to deal with.
     
  8. Flagg37

    Flagg37 Officer at large

    Not only that but the ratio of volume to surface area is much less with the larger plumbing.
     

Share This Page