Originally Posted by 2chesapeakes (Post 10877)

That should be a pressure relief. That type of dewar may take a while for the pressure to build to a point where you can use the valve to dispense. I had rented one similar to that and after a number of hours there was still not enough pressure built up to use the valve to extract the LN2. The dewar I have now is classified as a pressurized dewar. It is designed to build and maintain 22PSI. I can usually start dispensing immidiatly after it is filled. As for dispensing I looked at the hoses they sell to dispense then went to a hardware store and purchased a flexible 1/2" gas line and it fit perfectly to the valve.