16 
BULLETIN 57, U. B. DEPJLRI^IEXT OF AGRICULTURE, 
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 maybe placed in the base- 
ment or underground, thus 
keeping the water cool and 
preventing freezing. Figure 
1-4 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 1 5 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 neces- 
sary that about one-third of 
the computed storage capacity be added to provide space for the 
compressed air. The following table gives commercial sizes of pneu- 
matic tanks: 
Fig. 13.— Gravity supply system with storage tank on 
windmill tower. 
