Refering to the image uploaded can we say by applying bernouli equation and darcy equation the following : Pa/(guamma) + Va^2/2.g + Za - (head loss in pipe ab using darcy equation )-(head lossin pipe bc using darcy equation) = Pc/(guamma) + Vc^2/2.g + zc . ?? and the same thing between point a and point d ? if we can do so , thn the head loss in pipe ab must be diferent thn the head loss in pipe bd with a value that is equal to the difference between the dinamic velocities energy in c and d ? am I right ??? why we used to say that head loss are both equal in pipe bc and bd ??? P.S : pc and pd are at 0 atmospheric pressure .