An LN2 supply tank is a pressurised, vacuum-insulated vessel used to store bulk liquid nitrogen for dispensing into laboratory storage dewars. Unlike open-neck laboratory storage dewars used for sample storage, LN2 supply tanks are pressurised vessels operating at higher internal pressures – typically between 5 and 10 bar – and are fitted with pressure building coils, pressure gauges, liquid withdrawal valves, and pressure relief devices. They are the on-site reservoir from which laboratory storage vessels are topped up, eliminating the need for frequent cylinder deliveries in higher-volume environments.
In a fertility clinic context, the LN2 supply tank represents the bridge between the bulk supply chain and the individual sample storage dewars. Its sizing must be based on the clinic’s total daily LN2 consumption across all storage vessels, with enough capacity to cover the scheduled delivery interval plus a meaningful safety buffer for delays.
The pressure relief valve on an LN2 supply tank is a critical safety component. It must never be disabled, blocked, or manually adjusted beyond manufacturer specifications. LN2 supply tanks as pressurised vessels are subject to the Pressure Systems Safety Regulations 2000, which require a written scheme of examination, regular inspection by a competent person, and documented maintenance records.
The connection between the LN2 supply tank and the individual laboratory dewars should use vacuum-jacketed transfer lines where possible to minimise LN2 flash loss during transfer. Uninsulated transfer connections waste LN2 through evaporation during every fill operation and increase the volume of cold gas released into the storage room, which has ventilation and oxygen depletion implications.
Monitoring of the LN2 supply tank level is as important as monitoring the individual storage dewars. A supply tank that runs low without triggering a reorder is the upstream cause of most LN2 supply failures in active IVF programmes. Level monitoring with automated low-level alerts, and a documented reorder procedure that activates before the minimum safe level is reached, should be part of every clinic’s LN2 supply management framework.
Cryolab supplies LN2 storage vessels and can advise on supply infrastructure specification for fertility clinics and laboratories. Browse the storage vessel range or contact the Cryolab team to discuss your supply infrastructure requirements.
