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21081123 A
MVE TS Quick Reference Guide
Dewar Plumbing Connections
Connect a transfer line (included with freezer) from an LN2 supply tank to the fill connection at the rear of the
freezer. Optimum supply tank pressure is 22 to 35 psi (1.5 to 2.4 bar). Although the plumbing assembly has a
50 psi (3.45 bar) pressure relief device, it is recommended that the supply tank be pressurized below 35 psi
(2.4 bar) to reduce the LN2 “flash-off” rate during filling and to maximize the cryogenic valve life. The supply
line can be insulated to minimize LN2 transfer losses. After the transfer hose is securely coupled to the freezer
and supply tank, ensure all connections are leak free by opening the valve of the LN2 supply tank and apply a
soap and water solution to each field joint. You should not see bubbles forming at any joint. Wipe away excess
soap and water when finished. Before removing the transfer hose, ensure the LN2 supply tank valve is closed.
Slowly and carefully loosen the transfer hose connection to vent any remaining pressure in the line before
disconnecting the hose.
