TESTS OF DRAINAGE PUMPING PLANTS. . 19 



TEST OF PUMPING PLANT IN SUBDISTRICT NO. 3, LAFOURCHE DRAINAGE DISTRICT 



NO. 12. 



DESCRIPTION OF PLANT. 



This plant consisted of duplicate units, each having a 30-inch 

 Lawrence double-suction centrifugal pump driven by a 14 by 16 inch 

 Lawrence vertical slide-valve engine. The suction openings on the 

 pumps are 24 inches in diameter. The intake and discharge pipes 

 have been tapered and enlarged so that the area of the intake is 2.9 

 and the area of the discharge 1.8 times the area of the discharge 

 nozzle of the pump. The pumps were direct connected to the engines 

 by flexible couplings. The exhaust of the engines was conducted 

 through a common pipe to a water heater and then discharged into 

 the air. Steam was generated by two return tubular boilers of 

 100 boiler horsepower each. The boilers were in a brick setting 

 covered with asbestos. The fuel used was Mexican crude oil. Steam 

 was used to atomize the oil in the furnaces and to run the usual oil 

 and boiler feed pumps. The machinery was housed in a corrugated- 

 iron building. The average lift was probably less than 3 feet and 

 the maximum lift about 7 feet. The level of the water on the dis- 

 charge side varied about 2 feet. The area drained is 2,260 acres. 



METHOD OF CONDUCTING THE TEST. 



It was necessary to siphon considerable water into the district 

 the day before the test in order to have enough water to make a test 

 of both units. As a result the lift jyas low at first, but rapidly 

 increased to 4 feet at the time of the last reading. A five-hour test 

 was made on unit No. 2, but it was necessary to stop the test of 

 No. 1 after four hours to prevent the debris which had collected 

 around the suction screen from breaking the screen. At noon it 

 was necessary also to shut down one boiler, as the parts of one of the 

 valves in the boiler feed line became detached from the valve stem 

 and jammed so that no water could be pumped into the boiler. 

 By forcing the remaining boiler both pumps were run until the 

 necessary adjustments could be made, although the steam pressure 

 dropped. 



The [jumps were operated at such speed that they slightly exceeded 

 their rated capacity during the earlier readings. Toward the last, 

 especially niter the steam pressure dropped, they were running 

 somewhat under then- rated e.ipacity. The discharge of the pumps 

 was measured hv means of a Pilot tube if) each discharge pipe at 

 disl ' iihouf \'l feet from the pump. The first residing taken 



on unit No. 2 was inaccurate as to quantity pumped, as the velocity 



of the Witter was too great to he measured with the Pitot luhe. 



Gag< '■( in the still water in the suction and discharge canals 

 were read to obtain the actual lift. This lift was used in computing 



