Standard liquid nitrogen storage dewars are non-pressurised open-neck vessels, operating at atmospheric pressure. If your application requires liquid nitrogen dispensing under controlled pressure, a pressurised dewar with a pressure-building circuit is the correct choice. These are distinct product categories. For static cell and sample storage, a non-pressurised vessel storage configuration is safer and simpler. Cryolab offers both types and provides specification consultation to ensure facilities are not purchasing pressurised vessels for applications that do not require them.