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~ ."-~ / '~ ' ~ ,; .' ~---- ._----- ,...1 _. .~.." ,,~~"~ . -_.. _.--_..~~. -,-_.~~-- .~, Figure 3.--Barbed fitting at the end of the pipe used for jet- ting a hole from the trunk of each tree to the trench containing the corrugated pipe. The delivery hose is slipped over this fitting and is thereby drawn into the hole when the jetting pipe is retracted. Figure 4.--Downward view of delivery hoses installed in a corrugated pipe lying in a trench ready to be backfilled. operating. This head loss in the lateral is then compensated for by lowering the point of attachment of the supply hose from one tree to another a distance equal to it. Figure 5 gives the head loss gradient as a function of flow rate for several diameters of corrugated pipe. The flow rate within any section of the lateral pipe equals the flow rate to each tree, multiplied by the number of trees served beyond that section. For a given pipe diameter, the head loss for each section can be found from Fig. 5 by determining the head loss gradient corresponding to the flow rate within it, and multiplying this by the length of the section. The total head loss for the lateral is the sum of the head losses for each section. In designing a system, it is necessary to choose a lateral diam- eter that keeps the total head loss less than the head available at the water source. A convenient way of estimating the total head loss with uniformly spaced outlets along a lateral without calculating it sepa- rately for each section is: First, obtain from Fig. 5 the head loss that would occur if the inlet flow ran the full length of the lateral. Then illultiply this number by a reduction coefficient, F, to cOllipensate for discharge along the line. Reduction coefficients for various num- bers of equally spaced outlets are given in Table 1. Also, the head loss across each delivery hose is needeci before the hoses can be attached to each tree at the appropriate eleva1(!J'(J2965 -5-