Chapter 14. -PIPING, FITTINGS, AND VALVES 



CROSS 



11.316X 

 Figure 14-10.— Types of globe valve bodies. 



Figure 14-11.— Cross-sectional 

 globe stop valve. 



38.117 

 view of 



the boiler stops, the feed stop valve, and many 

 guarding valves and line cutout valves are of 

 this type. Globe valves are also used as stop 

 valves on the suction side of many pumps, as 

 recirculating valves, and as throttle valves. 



Gate Valves 



Gate valves are used when a straight-line 

 flow of fluid with a minimum amount of restric- 

 tion is required. Gate valves are frequently 

 used in water lines; for example, firemain cut- 

 out valves are usually gate valves. They are 

 also used in steam lines, particularly on the 

 newer ships. In fact, there appears to be an in- 

 creasing trend toward the use of gate valves 

 in many systems on new construction. 



The part of a gate valve that serves the same 

 purpose as the disk of a globe valve is called 

 a gate . The gate is usually wedge-shaped, but 

 some gates are of uniform thickness. When the 

 gate is wide open, the opening through the valve 

 is the same size as the pipe in which the valve 

 is installed. Therefore, there is very little re- 

 sistance to flow and very little pressure drop 

 through this type of valve. Gate valves are not 

 suitable for use as throttling valves, since the 

 regulation of flow would be difficult and since 

 the flow of fluid against a partially opened gate 

 would cause extensive damage to the valve. 



WHEEL NUT 



BODY 



11.317.1X 



Figure 14-12.— Cutaway view of globe 

 stop valve. 



373 



