Chapter 14. -PIPING, FITTINGS, AND VALVES 



VOLATILE LIQUID 



VALVE 



REPLACEABLE 

 HERMETICALLY 

 SEALED BELLOWS 



(a) TRAP COLD: VALVE OPEN 



VAPOR 

 VOLATILE LIQUID 



(b) TRAP HOT; VALVE CLOSED 



11.326X 



Figure 14-6.— Thermostatic steam trap. 



LOCK NUT 



STRAINER ' 



CYLINDER STEM 



CONTROL 

 ORIFICE 



TO HIGH PRESSURE 

 _^ORAIN SYSTEM 



CONTROL 

 ORIFICE 



38.126 



Figure 14-7.— Impulse steam trap. 



this principle is utilized, we will consider the 

 arrangement of parts shown in figure 14-7 and 

 see what happens to the flow of condensate under 

 various conditions. 



The only moving part in the steam trap is 

 the disk. This disk is rather unusual in design. 

 Near the top of the disk there is a flange that 

 acts as a piston. As may be seen in figure 14-7, 

 the working surface above the flange is larger 



than the working surface below the flange; the 

 importance of having this larger effective area 

 above the flange will presently become apparent. 

 A control orifice runs through the disk from 

 top to bottom, being considerably smaller at the 

 top than at the bottom. The bottom part of the 

 disk extends through and beyond the orifice in 

 the seat. The upper part of the disk (including 

 the flange) is inside a cylinder. The cylinder 



369 



