SPRAY IliHICATION. 



17 



have movable parts to assist in the distribution of water by cen- 

 trifugal force or water power. 



The efficiencies of nozzles found in use were determined by a series 

 of tests made under the direction of this office in 1909 and the re- 

 sults are here summarized. 



A popular solid nozzle (No. 4, fig. 11) was found to have a capa- 

 city of 1.93 cubic feet per minute (14.5 gallons per minute) under a 

 pressure of 20 pounds per square inch, and it gave a fair lateral 

 spread of 40 feet. Under 25 pounds pressure its capacity was 2.45 

 cubic feet per minute (18.4 gallons per minute) with a fair lateral 

 spread of 42 feet. The zone receiving the greatest amount of water 

 per square foot was found to be an annular ring about 15 feet from 

 the nozzle. This ring received about 40 per cent more water per 



Fig. 11. — Types of circular-spray nozzles. 



square foot than did the surface at 5 feet or 18 feet from the nozzle. 



A popular adjustable nozzle (No. 5, fig. 11) was found to have a 

 capacity of 0.98 cubic foot per minute (7.3 gallons per minute) 

 under 20 pounds hydraulic pressure and a fair lateral spread of 35 

 feet. Under 25 pounds its capacity was 1.23 cubic feet (9.2 gallons) 

 per minute and it gave a fair lateral spread of 38 feet. The nozzle 

 was opened one-half turn during the above test, which gives a 

 medium spray. A zone 12 feet from the nozzle received about 30 

 per cent more water per square foot than did the surface at 3 feet or 

 15 feet from the nozzle. 



A popular rotary nozzle (No. 2, fig. 11) was found to have a 

 capacity of 0.43 cubic foot (3.2 gallons) per minute under hydraulic 

 pressure of 20 pounds, and it gave a fair lateral spread of 32 feet. 

 66687°— Bull. 495—17 3 



