A fluid storage and dispensing system including a fluid storage and dispensing vessel containing a physical adsorbent material having sorptive affinity for the fluid to be stored in the vessel and subsequently dispensed from the vessel through a valve head assembly. The character of the fluid stored in the vessel, such as its pressure and/or temperature, is non-invasively monitored during the storage (non-dispensing) mode of the system, by a sensing element in the valve head assembly operative coupled with an output device such as a visual output display or a set point-limited alarm.