Marcet Boiler Technical Description This benchtop unit demonstrates the relationship between pressure and temperature of saturated steam. The saturation pressure curve can be determined up to a pressure of 15bar. A defined amount of water is heated in a pressure vessel using an electric heater. The temperature and pressure can be tracked continuously on a digital temperature display and a Bourdon tube manometer. A pressure relief valve and a high temperature cut-out are fitted as safety devices. Experiments with hot steam should only be performed under the supervision of trained personnel.