1898 



ENCYCLOPEDIA OP PRACTICAL HORTICULTURE 



Fig. 16. (11) A sectional view of a leakless 

 rod cutoff, showing the comparatively large, 

 straight passage-ways. 



per minute, depending upon the size of 

 the jet pump and how high the water 

 must be lifted. 



Piping and Cut-Offs 

 The piping used to carry the spray 

 liquid from the air chamber to some 

 convenient point for attachmen^of the 

 leads of high-pressure hose should be at 

 least one-half inch in diameter and make 

 as few turns as possible. The pressure 

 of the spray liquid at the nozzle is great- 

 ly reduced by friction of the solution 

 against the walls of the pipe if the 

 changes of direction are frequent, and if 

 the size of the orifices through which it 

 passes are small. The cut-off, at the 

 point of attachment of the hose lead, per- 

 mits the shutting off of one lead of hose 

 whenever desired, and this takes unnec- 

 essary strain off the hose which is not 

 in use. The three-way cut-offs, ordin- 

 arily furnished with machines, are al- 

 ways being turned in the wrong direction, 

 with the result that some one is fre- 

 quently drenched with spray liquid. Plain 

 cut-offs are superior to the globe valves. 

 See Fig. 14 (9). The latter usually change 

 the direction of flow very abruptly, and 

 soon become leaky, besides requiring a 

 lot of time to shut off the hose lead. Gate 

 valves are apt to become partially clogged 

 with sediment, which prevents their clos- 



ing properly, but they are superior to 

 the globe valves, because they are of 

 large capacity and do not change the di- 

 rection of the flow of the liquid. The 

 simple, leakless cut-off, shown in Fig. 15, 

 is positive in action, easily operated, does 

 not change the direction of the flow of 

 the liquid, is readily adjusted or repacked, 

 and is of large capacity. A sectional view 

 of the leakless rod cut-off is shown in 

 Fig. 16, giving an idea of the simplicity 

 of its construction. Just under the cap- 

 nut is a packing gland which allows any 

 slack in the valve to be taken up, and 

 also prevents any leakage. 



Hose, Hose Connections and Hose Bands 



The high pressures used in spraying 

 with modern power spraying machines 

 make the use of strong, heavy-walled hose 

 imperative. Half-inch high-pressure hose 

 of five, six, or seven-ply construction is 

 generally used for this purpose. The 

 heavier grades usually last enough long- 

 er, except where oil sprays are used, to 

 warrant their purchase. Three-quarter- 

 inch hose, having sufficient strength to 



Fig. 17. (12 and 13) Single-length hose con- 

 nections with round nut. The kind every 

 practical spraying outfit should not have. 

 (14 and 15) Double-length one-fourth inch 

 pipe-thread male and standard female hose 

 connections, permitting the use of two hose 

 bands of the Sherman type. These have a 

 hexagonal flange and hexagonal nut so they 

 can be adjusted with an ordinary wrench. 



