Mance: Quarry Industry of Southern Indiana 



73 



connection with the opposite piston rod. Two cylinders and 

 pistons cannot be packed so that friction will be equal in each, 

 hence the result is that one cylinder is interrupted and reversed 

 before it has had time to complete its stroke. In other words, 

 one cylinder is constantly short stroking. Another thing in 

 favor of the single pump is the fact that it has fewer ports and less 

 steam space to be heated and filled with waste steam. In speci- 

 fications of pumps for feed-water work the amount of water 

 necessary should be specified since the term horse-power in 

 referring to a boiler is a very indefinite term. The accompanying 

 cut represents a simple Dean Brothers pump. This pump is the 

 most widely used thruout the stone district. 



Feed-Water Pump 



The following suggestions concerning pumps are of im- 

 portance: 



1. A pump should be subjected to a pressure test of at least 

 200 pounds per square inch before purchase. 



2. It should show a suction of at least 25 inches of mercury. 



3. The piston of a pump used for feeding water to a boiler 

 should not run over 50 feet per minute. 



4. If possible avoid all right-angle turns in the suction pipe. 

 5., The pump must not be more than 20 feet above the 



water supply. For hot water it must be below the water supply. 



6. See that all water entering a pump is thoroly strained. 



7. Avoid leaks in the suction pipe. 



8. A check valve and water cock should be placed in the 

 discharge pipe. 



