



reason large outfits 



_ SPRAY IRRIGATION. fie 27 
for pumping from surface supplies to any height. They can be 
driven by either belt or gear connection to the power. 
Triplex or three-cylinder pumps are adapted for pumping water 
_ from surface supplies to any height of lift for the larger plants. For 
special well conditions triplex pumps are designed for the three 
cylinders to work in a pit while the power working head remains on 
the surface. These also can be driven by belt or gear connection to 
the power. 
Small displacement 
pumps of the _ belt- 
driven types should be 
equipped always with pA 
tight and loose pulleys ie 
to aid in starting the 
engine. For the same 

should be equipped 
with friction -clutch 
pulleys on the shaft if 
belt driven and shaft 
clutches if gear con- 
nected. Clutches are 
not so essential where 







































electric power is used a Tbs 
e an WAS 
for either small or oh \ 
large plants. All dis- 
placement pumps 
should be equipped 
with ample air echam- Fig. 17.—Typical power working-head for deep-well 
f pumps having a 24-inch stroke. 1, Air chamber; 
bers to act as cushions 2, crosshead guides; 3, piston rod; 4, connecting rod; 
in absorbing the pulsa- 5, packing gland; 6, tight and loose pulleys; 7, gear 
ons of ie soutien wheel; 8, base; 9, discharge opening. 
Relief valves or by-passes should be placed in the discharge pipes to 
prevent breaking the pumps or engines should all or a part of the 
spray lines be shut off. 

CENTRIFUGAL PUMPS. 
_ Centrifugal pumps can be classified as volute and turbine types. 
Each type can be divided further into pumps having one, two, etc., 
stages, according to the number of impellers contained. Figure 18 
shows a typical single-stage volute-type pump with exposed im- 
peller. Single-stage pumps are built in both volute and turbine 
types for any lift practical for spray irrigation; however, the possible 
Ww Ciena =e ee 8 ws eee a.) es ee 
— ee ee es os ne 
17 Se Soe 
