Can I hook together two liquid nitrogen transfer hoses? If so, what are the parts needed?
A. If your intention is to make one longer hose, make sure you add a blocked line relief valve. Good practice for any cryogenic plumbing includes a suitable pressure relief device in any line that could trap cold gas or liquid between two or more valves. You will need two stainless steel flex hoses, with the appropriate CGA connections for you gas on one end and 3/8 NPT male connection on the other end. Connect the two hoses together with a 3/8 FNPT tee. Add a relief valve to the tee to protect from over pressurization.
