I'm trying to design a plumbing system for a school project, and I want to verify that my initial piping layout from water source to outlets is logical before I start making calculations and programs for the system. Here is my drawing, thanks to Rhodie:

LAyout The green curve represents a hill that the building is on. My logic for this design was that by minimizing the number of fittings I have in my system I can reduce the required head I would need to generate by the pump and save some money.

Any advice or comments would be greatly appreciated!

  • $\begingroup$ My suggestion would result in 49m of horizontal pipe instead of your current 76m $\endgroup$ – Rhodie Nov 23 '18 at 0:33
  • $\begingroup$ Apologies, 21m vs your 31m $\endgroup$ – Rhodie Nov 23 '18 at 0:35

My first question is why would you want that length of pipe? The total length could be substantially reduced if the vertical pipe was placed close to point 1. Your materials cost would be halved. The way to calculate the best vertical point would be to spur outlet 1 straight from the riser and the other 2 distant outlets from that same single riser.

Pressure head has nothing to do with number of fittings. It is calculated according to gravity×vertical volume of water above inlet: your pump.

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  • $\begingroup$ Is the number of fittings not related to the minor loss of head? My fluids textbook pretty much says thats where all of the minor head losses will come from. The location of the building relative to the source is fixed, but I do see your point. Ill do some optimization on the location that the piping first goes vertical and see how much pipe I can save. $\endgroup$ – WhisperingShiba Nov 23 '18 at 0:27
  • $\begingroup$ Minor... is the operative word $\endgroup$ – Rhodie Nov 23 '18 at 0:28
  • $\begingroup$ The fittings at friction and turbidity to fluid flow but the head is directly affected by the height above the pump which has to work against gravity and mass $\endgroup$ – Rhodie Nov 23 '18 at 0:29
  • $\begingroup$ is it typically acceptable to completely neglect minor losses in a system like this? Its not part of the assignment specifically, I'm just looking at the equations and considerations I need to make before I start, so if I can ignore it I'm actually happy! $\endgroup$ – WhisperingShiba Nov 23 '18 at 0:29
  • $\begingroup$ Usually a system is overdesigned to make allowances for waterhammer which is far more destructive than minor fitting head pressure losses. $\endgroup$ – Rhodie Nov 23 '18 at 0:31

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