Maximum Surcharge Height Over Crown Explanation

Note:   Maximum Surcharge Height Over Crown Explanation 

 Here is an example of how the Maximum Surcharge Height over the Node Crown is calculated.     Consider a manhole with an invert of 10 feet,  one incoming pipe (Pipe A), one outgoing pipe (Pipe B), both pipes with a diameter of 2 feet, but the invert  of Pipe A is 10 feet and the invert of Pipe B is 11 feet.  What is the Maximum Surcharge height if the HGL at the node is 17 feet?

                                                                                 HGL at Node ---- 17 feet

                                                                                Maximum Surcharge Height Over Crown is 4 feet


                                                                                Node Crown --- 13 feet         Pipe B Crown --- 13 feet                          


           Pipe A Crown --- 12 feet                          


                                                                                                                                    Pipe B Invert --- 11 feet                          

            Pipe A Invert --- 1o feet                           MH Invert --- 10 feet