initial pressure less than vapor pressure how to resolve as I am new to this forum unable to resolve

Question

DEar

Jesse Dringoli · Answer

Hello, 
 You had posted in the Licensing, Cloud and Web Services forum. I have moved your post to the OpenFlows product community forum where you can get help with technical questions about the OpenFlows software (I assume you are using HAMMER). 
 In HAMMER, if the initial conditions pressure is less than the vapor pressure limit (set in the transient calculation options), it means there would be a vapor pocket at that location, so the initial conditions are invalid. You will need to examine the area identified by the message and determine the cause of the very low pressure. See more guidance in the following articles from our Wiki: 
 
 User Notification: "Initial pressure less than vapor pressure. At the pipe end(s), the elevation(s) or head(s) are incorrect" 
 Does HAMMER support initially negative pressures? 
 Troubleshooting negative pressures at pumps, junctions, & other node elements

Jesse Dringoli · Answer

D PRADHAN said: Can you help me in solving the errror i.e. global pressure dependednt demand function is underdefined. 
 This indicates that you have selected "True" for the "Use Pressure Dependent Demand?" calculation option but did not select a Global function in the Pressure Dependent Demand alternative. The calculation option is found near the bottom of the list in the Initial Conditions solver calculation options.. 
 You will need to open the PDD alternative, set up and select the global function. 
 See more here: Using Pressure Dependent Demands 
 If you have any additional questions, please start a new forum thread. 
 If you are new to HAMMER, you may want to review the WaterCAD/WaterGEMS fundamentals training (for the initial conditions / steady state) and the HAMMER training, found here: 
 
 Learning Resource Guide for new users of WaterGEMS and WaterCAD 
 Learning Resource Guide for new users of HAMMER