Procurement asks an entirely reasonable question when two vessels of the same capacity return different prices. The honest answer is uncomfortable: capacity is the only thing those two quotations have in common, and it is the specification that matters least.

Running Cost: The Number That Decides the Ten Year Figure

A cryogenic vessel consumes liquid nitrogen continuously whether you use it or not. The static evaporation rate sets that baseline, and across a decade the gap between a good rate and a poor one routinely exceeds the difference in purchase price between the two vessels being compared.

So the first question is not what the vessel costs but what it costs to run. Two figures belong in every quotation: the static evaporation rate, and what that translates to as a weekly nitrogen order for your capacity. Where neither appears on the specification sheet, ask for both in writing.

A supplier who will not put the evaporation rate in writing is telling you something about the evaporation rate.

Inside the Wall: What the Difference Is Actually Made Of

The insulation in these vessels is a vacuum, and vacuums are not equally good.

Better vessels carry more layers of multilayer insulation, cleaner internal materials that outgas less, and a larger getter, the chemically active component that absorbs stray gas molecules and holds the annulus evacuated. Getter capacity is a direct determinant of how many years the vessel holds its performance.

None of that is visible on delivery and none of it appears on a comparison table. All of it costs money to build, and all of it reappears later as evaporation rate and as service life. This is the single largest source of legitimate price difference between two vessels that look identical on paper.

Build Quality: Visible Only as a Failure

Neck construction, internal support design and weld quality decide whether a vessel survives being caught by a trolley. A mechanical shock can crack a weld or fracture an internal support without leaving any external evidence, and the vacuum then degrades quietly from that point.

A vessel specified for a store room it never leaves is a different build from one moved between rooms weekly, and the cheaper quotation is frequently the former being sold for the latter.

Safety Devices and Compliance: Not Optional Extras

BCGA Code of Practice 36, which covers cryogenic liquid storage at users premises, requires at least two independent safety devices on the inner vessel of a pressurised tank, typically a pressure relief valve and a separate bursting disc, with the outer jacket relief device set to open at not more than 0.5 bar.

A quotation that omits that arrangement is not a cheaper version of the same thing. It is a different product.

Where a vessel operates above 0.5 bar above atmospheric pressure, the Pressure Systems Safety Regulations 2000 require a written scheme of examination drawn up by a competent person, and HSE guidance INDG178 sets out what that scheme must cover. That is a recurring cost attached to the vessel, and it belongs in any honest comparison.

Monitoring: In the Number or Out of It

The ESHRE recommendations on Good Practice in the IVF laboratory, in Human Reproduction (41(8), 1245), expect cryostorage tanks to be continuously monitored with alarms that detect and log out of range temperature or LN2 level.

Larger vessels frequently include level, temperature and power alarms with a remote output. Smaller ones generally do not. A vessel that appears cheaper because monitoring was excluded is quoting an incomplete installation, and the relay to a building management system or autodialler is a further line that is easy to leave out and expensive to leave out.

The Items That Arrive After the Order

Roller bases and trolleys for moving vessels without manual handling risk. Racks and canisters matched to your straw format rather than to a reference format. A dispensing dewar such as the CryoCrest 35L or 50L, which uses a manual aluminium foot pump so there is no gas pressure to manage while pouring. A dipstick for the daily manual check. Cryogenic gloves, apron and face protection for the people who will handle it.

None of these is expensive individually. Collectively they are the reason a budget built from a single line item runs short, and the full list is set out in our cryopreservation equipment procurement guide.

The Price of the Liquid Nitrogen Itself

There is no list price for liquid nitrogen in the way there is for a consumable. It depends on your supply arrangement. Bulk delivery to a static tank, cylinder delivery and self collect all price differently, and delivery frequency is driven by how quickly your vessels boil off.

Which returns the argument to evaporation rate, and explains why the cheapest vessel is often the most expensive decision on the page. It raises a recurring cost you will carry for a decade in exchange for a single saving at the point of purchase.

Why There Are No Figures in This Article

Cryogenic vessel pricing depends on specification, configuration, monitoring, delivery and prevailing supply conditions. A number published here would be wrong for most readers by the time they read it, and an indicative figure that proves inaccurate is worse than no figure at all.

What we will do instead is quote against your actual requirement and state the static evaporation rate and expected weekly nitrogen order alongside the price, so the comparison you make between us and anyone else is a comparison of the numbers that matter. Speak to Cryolab and we will put all three in writing.