'Note on Some ExperIxMents With a New Form of Pressure 



Regulator. 



William Kendrick Hatt. 



rjeneral.— Tlie writer here records some experiments which were made 

 under his direction in the Engineering Laboratory of Pm-diie University 

 on a new apparatus by Mr. Will Hull, of the class of 1001. who developed 

 the details of the apparatus from the suggestion of Mr. .1. T. Wilkin, 

 engineer for the Connersville Blower Company, Counersville. Ind. 



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

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

 the disc being enclosed in n suital)le 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 pressui'c foi'cing tlie Iiall against the jet is 

 the pressure of the atmosphere. In the a|iparatus here desci-ibcd tlie disc 

 is enclosed in a chamlier. .-md tlie back pressure is the pressure of the 

 water in the chamlier. This pressure is greater than Tliat in the rapidly 

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

 moves toward the nozzle until e(Hiilibrium is cstalilished. The disc thus 

 automatically throttles the up-stream. 



When this apparatus is inserted in a iiipe line the pressure on the 

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

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

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

 The principle of the apparatus will have an a|)])lication 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 readied which would regulate the pressure in case of 

 jiir or steam is not determined. 



The experiments were initiated with the desire to olttain infctrmation 

 which would serve as a l)asis for proportioning this apparatus to serve 

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

 rupted before that ix)int 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 iu case 

 of the api)aratus availai>le. 



