From ASABE definitions 2.13 manifold: The water delivery pipeline that supplies water from the submain or main to the laterals. Manifolds

i.e.manifold

Manifolds

Pressure Regulation Design Strategies 1.Pressure regulating emitters 2.Pressure regulator at the head of each hose 3.Pressure regulator at the head of each manifold

Pressure Regulation Design Strategies Critical path: the hydraulic path that has the most pressure requirement from the water source (p137)

Pressure regulation at the head of each block If you ignore: Non-uniformity due to unequal set times or spacings Unequal drainage Uneven pressure regulator settings

Pressure regulation at the head of each block Then… DU system = DU block = DU lateral times DU manifold

Pressure regulation at the head of each block 1.Define the system DU 2.Determine DU lateral that is better than DU system 3.Minimum allowable DU manifold = DU system/DU lateral

Pressure regulation at the head of each block

P311:Class Problem: Design Supply Manifold for 84 laterals (280’) Zero slope Drip Tape with an ID of 0.625” w/emitters at 16” Nominal Flow rate = psi Emitter discharge exponent: x = 0.6 Tape length = 400’ on both sides of manifold Inlet P to tape during irrigation = 10 psi Tape cv = 0.03 Desired new block DU = 0.90