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| Desired Emission Uniformity,%: | |
| Manifold inside dia, in: | |
| Friction factor | F Factors |
| Elevation change on manifold, ft:1 | |
| Lateral spacing, ft: | * |
| No. of laterals: | |
| Lateral flow, gpm: | * |
| Lateral inlet pressure, psi: | * |
| Lateral average pressure, psi: | * |
| Friction loss in lateral, psi: | * |
| Emitter discharge exponent: | * |
| Emitter coefficient of variation: | * |
| Number of emitters per plant: | * |
| Subunit flow, gpm: | |
| Calculated Manifold pressure losses, psi: | |
| Allowable Manifold pressure losses, psi: | |
| Manifold inlet pressure, psi: | |
| Allowable Pressure Variation in subunit,psi: | |
| Minimum Allowable Pressure in subunit, psi: | |
| Maximum Allowable Pressure in subunit, psi: |
Manifold inlet pressure should be less than the maximum allowable pressure for the subunit. If it is not, reduce the desired emission uniformity, and recalculate. If it is still higher than allowed at the lowest acceptable emission uniformity level, redesign the laterals (by shortening, using a larger diameter, or selecting a smaller flow rate) and/or the manifold (larger dia., fewer laterals) and again recalculate to obtain allowable pressure variations and emission uniformity.
If recalculations are required, reenter the lateral inlet pressure as
the sum of mimimum allowable pressure in subunit plus lateral friction
loss, as the inlet pressure changes whenever a new minimum pressure is
calculated.