Info For Group Members
Refilling Jordan Group 160 L Liquid Nitrogen Dewar
- Get two wrenches, earphones, and gloves.
- Remove rubber hose and liquid nozzle from dewar.
- Attach small refill nozzle to liquid port on dewar.
- Take dewar to filling station.
- Turn on light (this activates the vent and O2 sensor
as well).
- Make sure vent and liquid valves at source are closed.
- Attach vent hose to vent port on dewar and tighten.
- Open vent port on dewar fully (the pressure will decrease from 20
psi).
- Cool liquid hose by passing N2 gas through it for 30
sec-1 min
(aim hose toward vent).
- Attach liquid hose to liquid port on dewar and finger-tighten.
- Open liquid port on dewar fully.
- lowly open liquid N2 valve at source (start at ~30
psi).
- Tighten liquid hose connection after liquid N2 begins
to enter
dewar (ice will form on the liquid hose).
- Fill dewar at 60 psi (up to 70 psi is safe). Maintain
maximum dewar pressure ~20 psi.
- Note fill level continuously after dewar is ~7/8 full.
- Turn off liquid N2 at source when dewar is full
(indicated by
tank level and leakage of liquid N2 from source vent)
- Close dewar vent and liquid ports simultaneously.
- Open main vent at source.
- Remove vent hose.
- Remove liquid hose.
- Close main vent at source.
- Sign logbook.
- Remove dewar and turn off light.
- Return dewar to SCL 402. If using GHJ elevator, call lab
for assistance.
- Remove refill nozzle and reattach liquid nozzle and rubber hose
once dewar warms to room temperature (to prevent stripping of threads).
- Return wrenches to toolbox.