148 



WATER CONDUCTORS AND ACCESSORIES 



as an indicator of the gate position (see Figs. 71 and 72). For 

 gates which are installed in diversion dams for sluicing off excess 

 flood water in forebay ponds or reservoirs, the non-rising type is 



preferable, as it permits be- 

 ing submerged without being 

 damaged by floating ice. 



Tainter Gates. This type 

 of gate is occasionally used for 

 controlling the water passages 

 to the wheel chambers in 

 low-head developments, the 

 methods of application being 

 shown in Fig. 73. They are, 

 however, more used in connec- 

 tion with diversion dams. 



Gate Valves. There are 

 numerous different designs of 

 gate valves, the details of one 

 of the most improved designs 

 being illustrated in Fig. 74. It 

 is intended for high pressures 

 and consists of the stem, a 

 double disc and two bevel- 

 faced wedges, the wedges being 

 entirely independent of the 

 discs and working between 

 them. 



By the action of the stem, 

 which works through a nut in 

 the upper wedge, the discs de- 

 scend parallel with their seats 



FIG. 74. Ludlow Bronze Mounted 

 Double Gate Valve with Bolted 

 Stuffing Box. 



until the lower wedge strikes 

 the stop in the bottom of the 

 case. The discs and upper 

 wedge, however, continue their 

 downward movement until the 

 face or bevel of the upper 



wedge comes in contact with the face or bevel of the lower 

 wedge. The discs then being down opposite the valve opening, 

 the face of the upper wedge moves across the face of the lower 



A Case. B Cover of Bonnet. C 

 Stem or Spindle. D Packing Plate or 

 Stuffing Box. E Stuffing Box Gland or 

 Follower. F Stem Nut. GG Gates. 

 H Gate Rings. I Case Rings. J Top 

 Wedge. K Bottom Wedge. L Throat 

 Flange Bolts. M Stuffing Box or Fol- 

 lower Bolts. 



