52 



BULLETIX 906, U. S. DEPARTMENT OF AGRICULTURE. 



change in design. This valve is provided with a lift gate in the 

 bottom so that some of the water can flow to the lower hydrants with- 

 out having to be forced through each valve. A much smaller pipe 

 could be used for the main distributing hydrant if the spillway pipe 

 was set through the lower side of the hydrant, and set on an angle to 

 the underground pipe. Smaller spillways could also be used if this 

 plan was followed, without danger from entrapped air. 



Where sandy soil is to be irrigated, and furrows run on a gradual 

 grade it is often best to do away with the ordinary stand that ex- 

 tends above the ground. An orchard valve or alfalfa valve can be 



cemented to the riser, having the riser 

 cut off 4 inches to 6 inches below the 

 ground surface. If the valve is set in- 

 side the first tree and in every tree row 

 it will be no obstruction to cultivation. 

 Where sandy soil is encountered it is 

 often impracticable to attempt to run 

 a number of furrows between the rows 

 on account of the rapid percolation of 

 water into the subsoil. It is a common 

 sight to see sandy ground watered by 

 using the ordinary hydrant fitted with 

 4 to 6 outlet gates, and either allowing 

 all the gates to spill in one main furrow 

 or letting the water run over the top of 

 the stand. Where flooding or basin ir- 

 rigation is practiced there is no need of 

 a number of small outlet valves set in 

 one hydrant. 



Where flooding is resorted to for al- 

 falfa or orchards having very flat grades 

 and sandy soil, risers are set at con- 

 venient intervals that are capped with 

 a special lid. This cap can be removed 

 and a portable hood or hydrant attached 

 to it (fig. 36). There are a number 

 of different types on the market. The best portable hydrant can be 

 fastened to the riser before the cap on the riser is removed or 

 loosened. Portable pipe made from light-weight galvanized iron can 

 also be easily attached to these portable hoods. This arrangement is 

 often used where alfalfa is irrigated, but may be used to advantage in 

 orchards where soil or grades will not permit of furrows. 



Where steel pipe is used for distributing water, the outlet valves 

 are usually the common hydrants or faucets used in domestic water 







V 













PP 





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Fig. 36. — Distributing hydrant for 

 large irrigation heads, such as 

 are used in irrigating alfalfa. 



