Patent Number: 8,820,347

Title: Passive overpressure and underpressure protection for a cryogen vessel

Abstract: In a magnet system for MRI imaging comprising a superconducting magnet mounted within a cryogen vessel, apparatus is provided for controlling egress of cryogen gas from the cryogen vessel. The apparatus comprises a controlled valve linking the interior of the cryogen vessel to a gas exit path; and a controller arranged to control the valve. The valve is arranged such that a gas pressure in the cryogen vessel exceeding a gas pressure in the gas exit path acts on the valve to open the valve and allow venting of cryogen gas. The valve is also arranged such that a gas pressure in the cryogen vessel inferior to a gas pressure in the gas exit path acts on the valve to urge it closed, so restricting flow of gas into the cryogen vessel.

Inventors: Mann; Nicholas (Compton, GB)

Assignee: Siemens PLC

International Classification: G05D 7/06 (20060101)

Expiration Date: 9/02/12018