OpenBuildings™ Station Designer Help

Workflow of Pipe Sizing Utility

The sizing system works for both upstream or downstream scenario of flow of water.

A: Up-feed , and B: Down-feed piping system

It provides calculations for both closed-systems (pressurized) and open-systems (drainage).

A: Up-feed water system - a water distribution system in which water is supplied and fed upward through the vertical piping to the highest point of the system that may be fed, using the available pressure. The source involved here is pump, requires sufficient pressure to raise water to the pipe terminals.

B: Down-feed water system - is a water distribution system in which the water distribution main is elevated and located at the top of the pressure zone such as roof; the distribution-main supplies the risers that distributes water downward to the lowest point of the zone. The source here is usually a storage tank, adds advantage of gravitation.

The Pipe System Sizing utility provides the systematic way of computing and sizing the pipe through the interface based mechanism. The utility facilitates optimized system that during sizing Iterations, tends to utilize remaining pressure heads and get the flow working in vertical and elevated routes.

The Pipe Sizing utility undergoes following steps:
  • Load System
  • Number Sections/Components and populate summary table
  • Set units, design data, and flow parameters.
  • Check System
  • Compute Data, Recalculate
  • Map types and elements to Fitting Database
  • Pipe sizing table and fixing sizing, material, and flow capacities
  • Component loss coefficient tuning
  • Resize System - walk through actual resize / replace component
The following considerations are taken in the Pipe sizing design:

To calculate friction loss in a pipe

  • Find the flow rate you wish to put through that pipe.
  • Divide the length of pipe you have by 100 and multiply by the "Head loss per 100'" value.
  • You have now predicted the head loss in that particular pipe.
  • Pipe fittings and valves disturb the normal flow of liquid, causing head loss due to friction.

Overall head loss in a pipe is affected by a number of factors which include the viscosity of the fluid, the size of the internal pipe diameter, the internal roughness of the inner surface of the pipe, the change in elevation between the ends of the pipe and the length of the pipe along which the fluid travels.

To reduce friction loss in a pipe
  • Reduce interior surface roughness of the piping system.
  • Increase pipe diameter of the piping system.
  • Minimize length of piping system.
  • Minimize the number of elbows, tees, valves, fittings, and other obstructions in the piping system; replace 90 degree turns with gentle bends