ROUGH-AND-TUMBLE ENGINEERING 2^ 



A cross head pump consists of a pump barrel, a 

 plunger, one vertical check valve and two horizontal 

 check valves, a globe valve and one stop cock, with more 

 or less piping. We will now locate each of these parts, 

 and will then note the part that each performs in the 

 process of feeding the boiler. 



You will generally find the pump barrel located under 

 the cylinder of the engine. It is placed there for several 

 reasons. It is out of the way and it is a convenient place 

 from which to connect it to the cross head by which it 

 is driven. On some engines it is located on the top of or 

 at the side of the cylinder. The plunger is connected 

 with the cross head and in direct line with the pump 

 barrel, and plays back and forth in the barrel. The ver- 

 check valve is placed between the pump and the 

 water supply. It is not absolutely necessary that the first 

 check be a vertical, but a check of some kind must be 

 used. As the water is lifted up to the boiler it is more 

 convenient to use a vertical check at this point, 

 ahead and a few inches from the pump barrel is a hori- 

 zontal check valve. Following the course of the v 

 toward the point where it enters the boiler, you will find 

 another check valve. This is called a "hot water check " 



his check, or between it and where the v. 

 enters the boiler, you will find a stop cock, or it may be a 

 f valve Tlu-v both answer the same purpose. I will 



