Leak Characterization Apparatuses and Methods for Fluid Storage Containers

Abstract

An apparatus for determining a leak rate of a gas from a closed valve is disclosed. The apparatus may include a vacuum pump, a pressure measuring device, a monitoring device, and a computer. The vacuum pump may be configured to couple downstream of the closed valve and decrease the pressure of the downstream side of the closed valve. The pressure measuring device may be configured to couple with the downstream side and determine the pressure. The monitoring device may be configured to couple with the downstream side and monitor a gas, where the gas may be emitted from the closed valve and be characterized by a mass. The monitoring device may further be configured to determine the mass. The computer may be configured to control the vacuum pump based on the pressure, and determine the leak rate of the gas based at least in part on the mass.

1 . An apparatus for determining a leak rate of a gas from a closed valve, wherein the apparatus comprises:
 a vacuum pump, wherein the vacuum pump is configured to:
 couple with a downstream side of the closed valve, wherein the downstream side of the closed valve is characterized by a pressure; and 
 decrease the pressure of the downstream side of the closed valve; 
   a pressure measuring device, wherein the pressure measuring device is configured to:
 couple with the downstream side of the closed valve; and 
 determine the pressure of the downstream side of the closed valve; 
   a monitoring device, wherein the monitoring device is configured to:
 couple with the downstream side of the closed valve; 
 monitor a gas on the downstream side of the closed valve, wherein the gas is characterized by a mass of the gas that is emitted from the closed valve; and 
 determine the mass of the particles; and 
   a computer, wherein the computer is configured to:
 control the vacuum pump based at least in part on the pressure; and 
 determine the leak rate of the gas based at least in part on the mass of the emitted gas. 
   
   
   
       2 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 1 , wherein the closed valve comprises an upstream side characterized by the presence of the gas in a high pressure state. 
   
   
       3 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 1 , wherein the pressure measuring device comprises a manometer configured to communicate with the computer. 
   
   
       4 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 1 , wherein the monitoring device comprises a mass spectrometer configured to communicate with the computer. 
   
   
       5 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 1 , wherein the emitted gas comprise atoms or molecules that can be detected by said monitoring device. 
   
   
       6 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 1 , wherein:
 the monitoring device is further configured to:
 couple with a calibration gas leak source having a certain leak rate; 
 monitor a calibration gas from the calibration gas leak source, wherein the calibration gas is characterized by a mass of emitted gas; and 
 determine a mass of the of the calibration gas; and 
   the computer is further configured to:
 store a value representative of the certain leak rate, wherein the value is based at least in part on the mass of the calibration gas. 
   
   
   
       7 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 1 , wherein the apparatus further comprises an evacuation pump. 
   
   
       8 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 7 , wherein:
 the evacuation pump is configured to decrease the pressure of the downstream side of the closed valve to about 1 Torr; and   the vacuum pump is configured to decrease the pressure of the downstream side of the closed valve to less than about 1 Torr.   
   
   
       9 . The apparatus for determining a leak rate of a gas from a closed valve of  claim 7 , wherein the computer is further configured to control the evacuation pump based at least in part on the determination of the pressure of the downstream side of the closed valve, and wherein controlling the evacuation pump and the vacuum pump based at least in part on the determination of the pressure of the downstream side of the closed valve comprises activating the evacuation pump until the pressure of the downstream side of the valve is decreased to about 1 Torr, then deactivating the evacuation pump and activating the vacuum pump. 
   
   
       10 . An apparatus for determining a leak rate of a gas from a closed valve, wherein the apparatus comprises:
 a means for decreasing a pressure of a downstream side of the closed valve;   a means for measuring the pressure of the downstream side of the closed valve;   a means for controlling the means for decreasing the pressure of the downstream side of the closed valve based at least in part on the pressure;   a means for determining a concentration of a gas on the downstream side of the closed valve; and   a means for determining the leak rate of the gas based at least in part on the determined concentration of the gas.   
   
   
       11 . A method of determining a leak rate of a gas from a closed valve, the method comprising:
 decreasing the pressure of a downstream side of the closed valve;   determining the pressure of the downstream side of the closed valve;   monitoring a gas on the downstream side of the closed valve, wherein the gas is characterized by a concentration and a molecular mass; and   determining the leak rate of the gas based at least in part on the concentration or the molecular mass of the gas.