THE FEED WATER. 



packing between the steam chest and the cylinder should be 

 made of heavy manilla paper or light rubber, and must be 

 patterned from the planed surface top of the steam cylinder, 

 (not the lower part of the chest), and all holes must be care- 

 fully duplicated, so that the drilled holes at each end are 

 wholly unobstructed at their points of register with the cor- 

 responding holes in the chest. The packing under the valve 

 plate must be patterned from the faced top of water cylin- 

 der, and the packing over the valve plate from the bottom 

 face of the air chamber. The steam cylinder head must not 

 be packed with anything thicker than heavy paper or the 

 thinnest rubber. If a thick gasket be used, the piston will 

 overrun the ports, and its. operation be interfered with. 



Check-Valves. A check- valve allows the water or other 

 fluid to flow in one direction, by raising the valve from 

 its seat, but when water attempts to "back up/' or flow in 



the opposite direction, 



the valve prevents this 

 by closing. With any 

 style of boiler-feeder, a 

 check-valve is placed in 

 the feed-pipe, and usual- 

 ly near the boiler. Be- 

 tween the check-valve 

 and boiler is placed a 



SECTIONAL VIEW OF CHECK-VALVE. 



globe or angle valve 

 which may be closed, allowing the check valve to be opened 



