O-ring LF L1186503

An O-ring is a circular seal that sits between two metal faces in a water or steam circuit. When the faces are tightened, the silicone ring compresses and fills any microscopic gaps, preventing leaks under pressure. In espresso machines and water boilers, this seal keeps hot water and steam inside the circuit, maintaining consistent brewing temperature and pressure without dripping or loss of steam power.

The operator removes the worn seal with a pick, cleans the groove, and presses the new O-ring into place until it sits evenly all round. No adhesive or grease is needed; the silicone's natural grip holds it in position while the faces are bolted back together. Once tightened, the seal is tested by running water or steam through the circuit and checking for drips or weeping around the joint.

This O-ring is made of red silicone, a material chosen for its resistance to heat and to the mineral oils sometimes used in water circuits. Silicone remains flexible across the temperature range of a commercial boiler, so it does not harden or crack over repeated heating and cooling cycles.

The O-ring 0155 fits specific models of CIMBALI, COLGED, MBM and ELETTROBAR espresso machines and water boilers. It is listed in the catalogue under spare parts for beverage equipment.