Orifices are widely installed in piping systems to provide a regular and reproducible loss of pressure.  Orifices are often used to limit flow, or in branching systems, to balance or distribute flow as required through different parts of the system.


Pipe Flow Expert provides support for the following orifice types:


  • Sharp Edged
  • Round Edged
  • Bevel Edged
  • Thick Edged


To add a component with an Orifice: 


  1. Add a component to a pipe as described in the previous sections. 


  1. Type the name of the orifice in the Component Name field.


  1. Select the Sharp Edged, Round Edged, Bevel Edged or Thick Edged orifice type.


  1. The symbol appropriate for the chosen Component Type is selected by default.  The symbol can be changed by clicking the Symbol Scroll Up or Scroll Down button to select the component pressure loss image you want displayed on the pipe system drawing.


  1. Enter the appropriate data for the orifice type (see following sections).


  1. Click OK to save and add the orifice to the pipe.



Notes: 


In Pipe Flow Expert, orifice components are always positioned at the end of the associated pipe. The associated pipe defines the pipe diameter preceding the orifice. The pipe following the orifice defines the pipe diameter that follows the orifice. The preceding and following pipe may have the same diameter and this would represent an orifice in a straight pipe. If the preceding and following pipe have different diameters then this represents a transition section, where the pipe diameter may get smaller or larger following the orifice. The Pipe Flow Expert software supports all of these cases when performing orifice calculations.  


The component orifice screen includes a ‘helper’ to assist in calculating an appropriate orifice diameter (d0) value based on the flow rate at some inlet pressure, and the required pressure drop, as specified by the user.


In addition, there is an option that allows the software to automatically size the orifice when the whole system is calculated. In this case, the orifice diameter is automatically calculated such that it produces the required pressure drop in order to achieve a specified flow rate in the pipe, when considering all of the other flows and pressures throughout the system. The user can then review the size of orifice required, together with the additional technical information provided such as inlet and outlet velocities, the jet velocity ratio, and the inlet and outlet pressures.