14* ROUGH-AND-TUMBLE ENGINEERING 



acid. It should be practically m presence of 



free acids in any considerable proportions will cause the 

 pitting of the cylinder and the follower or the follower 

 bolts in the piston and stud bolts in the cylinder head. 



LUBRICATORS 



There are two kinds of lubricators used for traction 

 engine cylinder lubrication, hydrostatic lubricators and 

 oil pumps. The hydrostatic lubricator makes use of the 

 pressure of a column of water to force the oil into the 

 feed pipe. This column of water is obtained through the 

 condensation of the steam and forms a column of frum 

 one to two feet in height, depending upon how the con- 

 nections upon the lubricator are made up. In the single 

 connection lubricator the length of the water column is 

 from the top of the vertical loop to the bottom of the 

 oil reservoir, usually from twelve to fifteen inches. The 

 oil floats up through the sight-feed glass and from there 

 passes through the horizontal oil pipe to the main steam 

 pipe, where it is caught by the current of steam and 

 atomized on its way to the steam chest and cylinder. If 

 the oil is dirty it may cause trouble by forming an in- 

 crustation at the end of the oil nozzle in the sight-feed 

 glass, which may deflect the oil against the sides of the 

 glass, thus preventing it from flowing freely into the 

 cylinder. In these lubricators water is introduced at the 

 bottom of the reservoir. Oil i? forced to the top and out 



