Pipe Schedule Data:
The pipe roughness must be input even if it is not used. The Hazen-Williams option does not use it but the Darcy option does.
In order to enter the above data enter “Libraries/Schedules” and click on “New” button. Then enter the data in the above table, as shown below.
Click on Apply and then OK buttons.
Pump Data:
While we are in the Libraries menu we enter the following data for the fire pumps
Fire pump name – Weir type 120/45
Minimum flowrate = 10000 lit/min
Maximum flowrate = 30000 lit/min
In order to enter the above data enter “Libraries/Pumps coefficients unknown” and click on “New” button. Then enter the data in the above table, as shown below.
Click on Apply and then OK buttons. When the Apply button is clicked the dialog box will display the pump curve as shown below.
5.3.3. Initialisation (Back from Libraries):
Now we return to the initialisation phase by selecting the Options menu. The next step is to select the pipe type.
It is worth looking at a few discussion points first.
What is the difference between a pipe schedule and a pipe type? A pipe schedule is standard pipe data, which is entered into a library. A pipe type on the other hand is a pipe schedule out of the library, which is to be used in the current network. It also has associated maximum velocities (or maximum pressure drop per unit length), C-factor and pipe lining if applicable. For the network model we propose to set up the following
C-factor = 140
Maximum velocity = 6 m/sec
Lining = none
In order to do this, enter “Options/Pipe type” and click on “New” button. Then enter the data as shown below.
A short cut technique for entering the maximum velocity is the following. Enter 6 m/sec in one cell. Click on another cell. Click and hold the left button on the cell, which has the 6 m/sec already entered and drag the cursor down over the other cells in the maximum velocity column. Of course the maximum velocity could also be entered individually in each cell.
We have already completed the Display tab. We will return to the “Calculation” tab once again later but for the time being initialisation and library phases are complete. We can now go into the network input phase.
5.4. Network Input:
5.4.1. Stage 1: Input of Schematic Drawing
In the Tools bar choose the pipe tool as shown below:
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span style='mso-ignore:vglayout;;z-index:1;left:0px;margin-left:443px;margin-top:107px;width:138px; height:54px'
Go to the drawing area and click on a grid point, preferably on the lower left hand part of the drawing area.
Drag the tool in the Northwest direction until you reach the point where you want to change the direction. Press and hold the shift key on the keyboard. Click on the left button of the mouse every time you want to change direction. (In the network schematic we are drawing there are two changes of direction.) When you want to create the end node release the shift key and click on the left button of the mouse.
Then draw the other pipes as shown below and complete the pipe network.
Try and keep the same pipe labels because it will be easier to input the attributes later. This would be easier if you have the link display switched on in the display tools. See below.
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