Patent attributes
A system for cryogenic gas delivery includes a cryogenic tank configured to contain a cryogenic liquid and a gas within a headspace above the cryogenic liquid. The system also includes first and second vaporizers and a use outlet. A first pipe is configured to transfer gas from the headspace through the first vaporizer to the use outlet. A second pipe is configured to transfer liquid from the tank through the first vaporizer so that a first vapor stream is directed to the use outlet. A third pipe is configured to build pressure within the tank by transferring liquid from the tank through the second vaporizer so that a second vapor stream is directed back to the headspace of the tank. A first regulator valve is in fluid communication with the second pipe and opens when a pressure on an outlet side of the first regulator drops below a first predetermined pressure level. A second regulator valve is in fluid communication with the third pipe and opens when a pressure inside the tank drops below a second predetermined pressure level. The first predetermined pressure level is higher than the second predetermined pressure level.