Wilo-Sinum is the ideal solution for pressurisation, replenishment and degassing in closed heating systems where standard equipment with a diaphragm expansion tank reaches its limits. The automatic pressure expansion system for pumps includes an integrated pressure-maintaining, degassing and replenishment function for closed heating and cooling water systems. The large variety of closed tanks sizes allows it to be adapted to many applications to ensure constant system pressures. The system offers continuous degassing with three selectable operating modes. The digital and analogue inputs allow it to be optimally integrated into existing building management systems.