Is Findenser suitable for use under pressure? Pressure is not normally applicable to Findenser; it is typically used open to atmosphere at the top. If you would like to seal off Findenser (e.g. you want to stop air getting in and reacting with your chemicals), then you should use an oil bubbler or a chemistry balloon to prevent a build-up of pressure. Please be advised that the maximum pressure of all the glassware we manufacture is 0.5 bar above atmospheric pressure (also known as 0.5 barg, or 1.5 bar absolute pressure) – it should not be subjected to any significant pressure.