Method of discharging high pressure storage vessels

A master/slave tank system for storing hydrogen gas for a fuel cell stack, said system comprising:

• a master tank for storing the gas;
• at least one slave tank for storing the gas;
• a first line coupled to the master tank for providing the gas stored within the master tank to the fuel cell stack;
• a first pressure regulator and a second pressure regulator positioned in the first line between the master tank and the fuel cell stack, said first pressure regulator being closer to the master tank than the second pressure regulator;
• an electrically driven master tank shut-off valve positioned in the first line between the master tank and the first pressure regulator, wherein a differential pressure across the master tank shut-off valve could be relatively high based on the tank pressure;
• a second line coupled to the at least one slave tank for providing the gas stored within the at least one slave tank to the master tank, wherein the at least one slave tank provides the gas to the master tank on the second line as the pressure difference between the slave tank and the master tank changes when the gas is output from the master tank on the first line;
• and
• an electrically driven slave tank shut-off valve positioned within the second line, wherein a differential pressure across the slave tank shut-off valve is relatively low, said slave tank shut-off valve automatically closing the at least one slave tank in response to an increased differential pressure across the slave tank shut-off valve.

A master/slave tank system comprising:

• a first tank for storing a gas;
• a second tank for storing the gas;
• a first line coupled to the first tank for providing the gas stored within the first tank to a gas-using device;
• at least one pressure regulator positioned in the first line between the first tank and the gas-using device;
• a first shut-off valve positioned in the first line between the first tank and the at least one pressure regulator;
• and
• a second shut-off valve positioned within a second line proximate to the second tank, wherein a differential pressure across the second shut-off valve is relatively low, said second shut-off valve automatically closing the second line in response to a gas leak.