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Note on vSome Experiments With a Neav Form of Pressure 



Regulator. 



William Kendrick Hatt. 



General.— The writer here records some experiments which were made 

 under his direction in the Engineering Lal)oratory of Pm-due University 

 on a new apparatus by Mr. AYill Hull, of the class of 1901, who developed 

 the details of the apparatus from the suggestion of Mr. J. T. Wilkin, 

 engineer for the Conuersville Blower Company, Connersville, Ind. 



The apparatus (Fig. 1) consists essentially of an expanding nozzle 

 and a flat circular disc, against which the jet from the nozzle is directed, 

 the disc being enclosed in a suitable chamber. The action is similar to 

 that of the well-known ball nozzle, and the disc replaces the ball. In case 

 of the ball nozzle the back pressure forcing the ball against the jet is 

 the pressure of the atmosphere. In the apparatus here described the disc 

 Is enclosed in a chamber, and the back pressure is the pressure of the 

 -water in the chamber. This pressure is greater than that in the rapidly 

 moving sheet of water on the up-stream face of the disc, so that the disc 

 moves toward the nozzle until equilibrium is established. The disc thus 

 -automatically throttles the up-stream. 



When this apparatus is inserted in a pipe line the pi-essure on the 

 down-stream face of the disc is preserved fairly constant (within the 

 limits of the experiments and for certain range of pressure in case of the 

 apparatus used), while the up-stream pressure varies within wide limits. 

 The principle of the apparatus will have an application whenever it is 

 desired to deliver water at a constant pressure to a machine from a source 

 of supply subject to fluctuations of pressure. Whether a design of disc 

 and nozzle could be reached which would regulate the pressure in case of 

 air or steam is not determined. 



The experiments were initiated with the desire to obtain information 

 which would serve as a basis for proportioning this apparatus to serve 

 various conditions of pressure and delivery. The experiments were inter- 

 rupted before that point was reached. The results obtained and the ex- 

 ample are generally interesting and it seems worth while to record them. 



Mr. Hull used various combinations of disc and nozzle until he found 

 the proper combination which would- regulate the pressure used in case 

 of the apparatus available. 



