Volumetric Measurements 



An approach has been taken by Perry Sub- 

 marine Builders adopted from the Com- 

 pressed Gas Association which tests gas stor- 

 age vessels throughout the United States, as 

 well as other internally pressurized systems 

 such as pipelines. In this procedure (31) the 

 pressure hull is filled with water, each com- 



partment is sealed pressure tight, and the 

 hull is placed in a pressure tank (Fig. 5.24) 

 which is then flooded and pressurized. Each 

 vehicle compartment contains an efflux line 

 leading through the test tank to a bank of 

 graduated cylinders called volumeters. Small 

 preliminary pressure is applied to force out 

 pockets of air and shake down the system. 



UJ 



z 

 < 

 I 

 o 

 m 



O 

 > 



VOLUMETER 



TEST TANK 



INELASTIC REGION 



PROPORTIONAL 

 LIMIT 



OPERATIONAL PRESSURE 



ELASTIC REGION 



-INITIAL TAKE-UP 



-^»- 



PRESSURE INCREASING 



Fig. 5.24 Chart showing pressure-volume change during hydrostatic tank test. (From Perry Submarine Builders) 



274 



