Flamco. Flexcon Premium. These expansion vessels have a plastic membrane made of thermoplastic polyolefin (TPO). For use in closed heating and air-conditioning installations, also for cooling installations. Nitrogen gas charge for even longer pre-charge pressure retention. Max. working pressure: 3,0 bar. Max. flow temperature installation: 120 °C. Vessels compliant with EN13831. Min./max. membrane temperature: -10 °C/70°C. Suitable for glycol solutions up to 50 %. 15 year warranty after production date.