This Estella Caffe 236PECEM57 safety valve serves as a direct replacement for the one that came with your select expresso machine. This safety valve replaces a broken or missing part on your unit. When the pressure of the boiler reaches 1.4 bars, the safety valve will automatically release pressure to ensure the safety of the unit. It's compatible with select Estella Caffe ECTPM, ECMS, and ECEM series.