Consolidating Dewars Into a Large Vapour Phase Storage Tank: A Planning Checklist

A room full of manually filled dewars works until it does not. This checklist is for biobanks, IVF groups, blood and tissue banks and research facilities deciding whether to move to one or two large, automatically filled vapour phase tanks.

1. Is it time?

Consider consolidating when manual filling takes a real part of someone's week, weekend cover is hard to staff, inventories sit in several files, or the store needs a new vessel every year.

2. Count samples, not litres

Count what you hold, add expected annual growth for several years, and choose a rack layout for vials, straws or bags. Large vessels range from about 15,600 to 95,000 vials each.

3. Decide on one vessel or two

Two vessels let you split critical collections and service one without moving everything. Keep copies of irreplaceable material apart.

4. Plan the supply

An automatically filled tank needs a bulk liquid nitrogen supply sized for its consumption and your delivery interval.

5. Plan the room

A large full vessel can weigh over a tonne. Check floor loading, doors, the delivery route, ventilation and oxygen monitoring.

6. Commission before you move anything

Cool the new vessel, prove the alarms and remote notifications, and run it empty until temperatures are stable.

7. Move in witnessed batches

Record a new position for every sample and reconcile each batch before retiring the old dewars.

The full guide is on the Cryolab website: Moving from many small dewars to a large vapour phase store.