16 



BULLETIN 57, U. S. DEPARTMENT OP AGKICULTURE. 



THE PNEUMATIC TANK SYSTEM. 



The pneumatic tank system consists of a force pump, an air-tight 

 steel tank, necessary pipe, valves, fittings, etc., and power for operat- 

 ing the pump. The system 

 may be a small one operated 

 by hand, windmill, or small 

 engine, or it may consist of a 

 large pump operated by a pow- 

 erful engine with two or more 

 tanks of large capacity. The 

 tank may be placed in the base- 

 ment or underground, thus 

 keeping the water cool and 

 preventing freezing. Figure 

 14 shows a pneumatic system 

 with the tank in the basement 

 and supplied by a hand force 

 pump. This figure also well 

 illustrates the water plumbing. 

 Figure 15 shows the tank in the 

 basement supplied by a wind- 

 mill deep-well pumping outfit. 

 The tank may be set in the 

 ground below frost line close 

 to the well or house foundation . 

 In the operation of the pneu- 

 matic system water is forced 

 into the air-tight tank, thus 

 compressing the air into a 

 smaller space and creating an 

 air pressure which forces the 

 water to the discharge cocks. 

 In determining the capacity 

 of the tank, then, it is neco; - 

 sary that about one-third of 

 tlie computed storage capacity be added to provide space for the 

 compressed air. The following table gives commercial sizes of pneu- 

 matic tanks: 



-Gravity supply system with storage tank on 

 windmill tower. 



