Irricad

Hi,

Recently I was doing a Golf Course Design and use many VIH, I set the outlet default pressure at 65 psi in the Date Base and after running all the design steps I got a MAINLINE SUMMARY REPORT. It shows 59.3~59.6 psi in the "Require Pressure " column. I don't know where does it come form, an explaination will helps a lot. By the way, I also used some landscape heads (block system) in some zones in Tees. The pressure set up at 60 psi in Datebase and shows 63~64 psi in the MAINLINE SUMMARY REPORT. Could you help me of explaning that ?

Thanks in advance.

Sincerely,

Janet

Janet,

The answer is in the database settings.

For Mainline|Outlets the "Required Pressure" the Mainline Summary reports is the allowable minimum pressure.
Note the "Flow Tolerance % Above" and "Flow Tolerance % Below" in the Database Edit Outlet dialog. The minimum and maximum allowable pressures are calculated based on these settings. The calculation includes the nozzle "Flow Equation Index" and if this number is 0.5 then the pressure tolerance is twice the flow tolerance.

If you want to be notified of any VIH outlets running below the inputted pressure rather than below the minimum allowable pressure set the "Flow Tolerance % Below" to 0. You may wish to increase the "Flow Tolerance % Above" particulary if using LP Design, to give IRRICAD a larger tolerance range to select suitable pipes within.

Please note that a "Default Pressure" of 65psi in the database for the outlet only means this is the pressure the outlet dialog will pop up with in IRRICAD. This may be a commonly used pressure but you can change it in each design as required in the Mainline|Outlet or Zone|Outlet dialog.