PE 1.13) In continue, I defined pump profiles, time function, performance curve, PCV’s characteristics and PID function (including control type, gain and reset time) and MOV closure profile based on project’s available documents, suppliers information and some standards such as NFPA 15 and NFPA 20. Then I carried out simulation in PIPENET software. Here is the summary of most important scenarios:

PE 1.14) In the first scenario (Normal start-up), I assumed that pipeline is dry and two pumps start simultaneously by power ramp time function. The main result was that it takes a long time (550 sec) for the pipeline to start delivering water into the storage tank, however, it was acceptable by the client. The maximum surge pressure in this case was less …show more content…
This scenario would generate the maximum surge pressure in start-up case, because of the dead-end pipeline. This surge pressure (14barg), was however, less than network design pressure.

PE 1.16) another likely scenario (no. 5) that I envisaged was simultaneous shut down of both pumps while the line is full of water. Since one check valve is installed at the outlet of each pump, upon shutdown of pumps those valves and associated pipes would experience a severe back pressure caused by the huge amount of water inside the pipeline. Software outputs showed that a serious water hammering would happen in this scenario. My recommendation was to shut down pumps in sequence order, first pump A and then after a defined time interval, e.g., 2 minutes, pump B.

PE 1.17) The last probable scenario that I modelled was simultaneous start-up of both pumps while the whole pipeline is full of water. This case is prone to cause a considerable surge pressure. The software output graphs, however, showed that maximum surge pressure in this case was less than design