When we add a Sprinkler to the Boundaries database, we define the Sprinkler Min. and Max. Operating Pressures as shown below.
When we then place a sprinkler node on the Flowsheet, we can define the Exit Pressure from the Input tab of the Data Palette - see image below. So, if the sprinkler were to discharge into a building, the exit pressure is likely to be 1 atm. However, if the sprinkler is discharging into a pressurized vessel, you have the option of defining a specific local Exit Pressure (tank pressure etc).
