Pipe Flow Expert will allow the user to design pipeline systems with up to 20 different fluid zones. The density and viscosity of each fluid zone must be set by the user. Pipe Flow Expert does not calculate the resultant density or viscosity of any 'mixed' fluids.


Each pipe in a system can be associated with an available fluid zone. The density and viscosity of the associated fluid zone will be used in calculating the flow rate and pressure loss in each pipe.


Gas Systems:


When using the Compressible Gas Flow calculation engine, the density of the fluid will automatically be adjusted based on the pressure in the network at the point of the calculation. i.e. the software will automatically account for any compression and expansion of the gas in the friction loss calculations. This means that the fluid density and viscosity could be defined at normal atmospheric conditions and specified at say 0 bar.g, however the fluid data MUST be defined at the temperature condition that is present in the network, since the software needs to know what temperature the fluid is at.


For example, gas data could be defined at say 0 bar.g and 20 degrees C, and it would be ok to use this for calculating the system even if the pressure in the network were say 10 bar.g, provided that the temperature in the network was 20 degrees C. If the temperature in the network was say 50 degrees C then the fluid data should be specified for some pressure condition at 50 degrees C. 


Many systems will only have one Fluid Zone, therefore when a new system is being drawn each new pipe will be associated with the fluid zone associated with the default pipe data. Fluid Zone 1 is the Default Fluid Zone. The color of Fluid Zone 1 cannot be changed. Pipes in the default fluid zone are not background highlighted.


Pipes associated with Fluid Zone 2 to Fluid Zone 20 are background highlighted to assist with identification of the different fluid zones. The background highlight color for these fluid zones can be amended by the user. This background highlighting may be toggled on/off from a fluid menu option.


Changing the fluid data of a fluid zone will affect the calculation of flow and pressure loss for all pipes associated with the fluid zone.