592 



HYDRAULICS AND ITS APPLICATIONS 



The ordinary disc or double-beat valve suffers from the drawback that 

 the kinetic energy of the discharging streams is of necessity dissipated in 

 the shock accompanying the sudden change in the direction of flow. The 

 Haste and the Gutermuth valves are interesting examples of designs 

 intended to obviate this source of loss. The 

 action of the former is obvious from the sketch 

 Fig. 281. 



The Gutermuth valve (Fig. 282) is formed 

 from a single sheet of special bronze, either of 

 the same thickness throughout or, in large 

 valves, having the end forming the valve 

 thickened. The sheets are slightly wider at 

 the coiled end to prevent fouling, and are 

 slipped on to a grooved spindle and clamped 

 to the valve seat cones at the required tension. 

 The valve is always placed at an angle with 

 the port opening, and the latter thus becomes 

 uncovered with a very small movement of the 

 valve itself, while no such abrupt changes in 

 the direction of the escaping stream are neces- 

 sitated as in the case of disc or mushroom valves. 



The automatic or self-closing valve, while simple and satisfactory for 

 low velocities, possesses several disadvantages which tend to reduce its 

 suitability for high speed work. 



In the first place, with automatic suction valves, the difference of 





FIG. 281. Haste Valve. 



FIG. 282. The Gutermuth Valve. 



pressure below and above must be sufficient to lift the valve, and with 

 a heavy valve this appreciably diminishes the possible suction lift. A 

 light valve, by coming slowly to its seat at the end of the stroke, enables 

 water to leak back into the suction pipe, since, although theoretically 

 the valve is on its seat when the piston is at rest, actually this is not 

 by any means the case except at slow speeds. The same thing applies on 



