Pre 2014 Blogs

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

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