1 62 Book of Engineering 



perhaps the pass-out turbine is the best 

 example for all round stationary work. 



The main principle of this method of 

 working is that the low pressure steam, as 

 extracted from the turbine, is allowed 

 to do work in the high pressure stage 

 first. 



It also does away with a high back-pressure 

 turbine which is very inefficient. The 

 main advantage of this type of turbine is 

 found in cases where the demand for 

 low-pressure steam does not correspond 

 with the load, or where the demand is 

 not constant. 



Under such conditions, it would appear 

 that governing would be a very difficult 

 thing, but with a specially designed oil relay 

 governor, on which an isochronous gear is 

 superimposed, governing is brought within 

 the ordinary limits, and hunting is non- 

 existent. 



The method of controlling the amount 

 of steam being passed out is by means of 

 a ported gate, the ports being set in such 

 a way as never to allow them to close, this 



