ECONOMICAL USE OF FUEL IN CREAMERIES. 27 



If, however, the pump is at such a distance from the supply tank, 

 or the supply pipe has so many abrupt bends that the head of 3 feet 

 is not sufficient to force the required quantity of water through the 

 supply pipe close to the pump, the standpipe may be vented to the air 

 or back to the top of the supply tank. In either case the benefit of 

 the full head will be obtained at the pump. To pump hot water suc- 

 cessfully it is necessary to keep a solid body of water at all times 

 against the pump plunger, otherwise the pump will not operate suc- 

 cessfully. The packing for a pump required to pump hot water, of 

 course, should be adapted to the temperature it will have to with- 

 stand. 



STEAM LEAKS. 



But few realize the enormous indirect fuel loss caused by leaks in 

 the piping system. A single leak in itself does not appear to be 

 serious, but a number of leaks around valve steins, blow-off cocks, 

 jiipe flanges and unions, safety valves, and at other points through- 

 out the system will reduce the available horsepower of the boiler very 

 greatly and indirectly increase the quantity of fuel burned. For in- 

 stance, if the sum of the openings through which steam escapes to the 

 atmosphere should equal one hundredth (0.01) of a square inch and 

 the steam pressure in the piping is 75 pounds' gauge, or 89.7 absolute, 

 the amount of steam that will escape in one hour will be approxi- 



89.7X0.01 

 mately: — — »« " X60X60=46 pounds, or 1.3 boiler horsepower. 



Should these leaks continue to exist and the plant be operated 10 

 hours a day for 310 days in a year, the annual loss in steam would 

 be 46X10X310=142,600 pounds. This would require the burning of 

 21,283 pounds, or 10.6 short tons, of average coal to produce the 

 amount of steam mentioned, if we assume a boiler and furnace effi- 

 ciency of 50 per cent, which is greater than is found in most cream- 

 eries and milk plants. If the coal costs $5 a ton the money loss will 

 amount to $53 annually, to say nothing of the inconvenience, un- 

 sightly appearance, and deterioration of valves and fittings due to 

 the escaping steam. It is obvious therefore that all leaks should be 

 stopped as soon as they appear. 



HEAT LOSSES FROM BARE PIPE. 



But few Creamerymen insulate their steam piping. They are either 

 not aware or are negligent of the serious loss in heat that goes on 

 continuous!} 7 when pipes or apparatus carrying steam are left bare. 

 A square foot of bare piping inside a building will radiate about 3 

 B. t. u. 1 per hour for each degree difference in temperature between 



1 P». t. u.=British thermal unit, the amount of heat required to raise 1 pound of pure 

 water 1 degree Fahrenheit. 



