26 
BULLETIX 1067, U. S. DEPARTMENT OE AGRICULTURE. 
90 
80 
70 
60 
TEST OF PUMPING PLANT NO. 3, AVOCA DRAINAGE DISTRICT, ST. MARY PARISH, LA. 
DESCRIPTION OF PLANT. 
This plant is of especial interest, inasmuch as it is the only steam 
pumping plant in this section in which superheated steam is used. 
The equipment consists of a cross-compound Lentz engine, a water- 
tube boiler with2 ? 487 square feet of heating surface, a 72-inch centrif- 
ugal drainage pump with two 48-inch suction pipes, a superheater 
composed of 2-inch elements about 6 feet 2 inches long (amount of 
surface unknown), a condenser, a duplex service pump which sup- 
plies water to the open heater and to the water seal of the centrifugal 
pump, and a duplex pump which takes the water from the heater and 
forces it into the boiler. 
The engine cylinder dimensions are 18+ and 31 inches with a 21- 
inch stroke: the rods are each 4 inches in diameter. The valves are 
of the poppet type, op- 
erated by eccentrics 
and cams from a lay 
shaft with axis parallel 
to that of the cylinder. 
The conditions for op- 
erating the engine called 
for a pressure of 175 
pounds at the throttle. 
Vj" /&*$P -®® degrees of super- 
is *#« /A ^ heat, and 26 inches of 
vacuum. The super- 
heater was not erected 
in the direct path of 
the hot gases . and there- 
fore the superheat is 
less than 200 degrees. 
The condenser is of the 
jet type. The boiler 
walls are lagged with 
cork, which is in turn covered with cement mortar. The suction and 
discharge pipes of the pump are greatly increased in cross-section at 
their outer ends. 
The test was begun in the morning and continued through the day. 
but as there was no provision for lighting the plant except by oil 
lanterns it was discontinued when night came on and resumed the 
next day. 
The oil used during the test was Oklahoma crude oil with a specific 
gravity of 0.885 at 92° F. The quantity used was weighed in a bucket 
on a spring balance. The feed water was pumped through a hot- 
water meter. At the close of the test an attempt was made to call- 
^50 
>*40 
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asf 
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(4 
$ 
f x 
I 2 3 4 5 6 7 
Acfua/ /iff in feet 
8 
Fig. 2.— Efficiency of pumping plant No. 3,Avoca drainage dis- 
trict, as indicated by test of Sept. 13 and 14. 1911. 
