ACCUMULATORS 



721 



machinery for training the heavy guns, rotating turrets, etc., is very 

 general, but here, for obvious reasons, the accumulator loaded with a mass 

 of pig iron weighing many tons is quite inadmissible. 



In its place the steam accumulator (Fig. 346) is used. This consists of 

 i steam cylinder fitted with a piston and its piston rod or ram, which 

 takes the place of the weight -loaded ram of the ordinary type. Steam 



iSteam to 

 Pumping Engine 



To Motors 



FIG. 346. Steam Accumulator. 



from the boiler is admitted to the upper side of the piston, first passing 

 through a reducing valve which ensures a constant pressure, and with a 

 given steam pressure P, a suitable adjustment of the areas A g and A of 



the steam piston and ram, will enable any required hydraulic pressure, 

 ^ 



p = P -~ Ibs. per square inch, to be maintained. The steam supply to 

 A 



the pumping engines is taken through the steam cylinder, and the accumu- 

 lator piston automatically cuts off this supply on reaching a given height, 



H.A. 



3 A 



