O-ring SCHAERER Spare Parts 3323817000

An O-ring forms a flexible seal between two surfaces, blocking leaks of water, steam or air under pressure. The circular cross-section is compressed between the mating parts, creating a continuous barrier that keeps fluids inside the system and contaminants out. This principle is essential in coffee machines where hot water and steam must travel at controlled pressures without escaping or mixing with cooler zones.

To use the O-ring, the operator first shuts off the machine and releases any residual pressure. The old seal is removed from its groove, the seating area is cleaned of scale or residue, and the new O-ring is pressed into place without twisting or stretching. Once the mating surfaces are reassembled, the machine is restarted and checked for leaks around the joint.

The O-ring is moulded from VMQ (silicone) with a Shore A hardness of 65, giving it the balance of flexibility and resilience needed for repeated thermal cycles. Its dimensions—37.6 mm inside diameter and 2.69 mm cross-section—match the grooves in the specified SCHAERER coffee equipment, ensuring a precise fit that does not deform under operating pressures.

The Shore A hardness of 65 means the material resists permanent compression, so the seal remains tight over many heating and cooling cycles. Silicone VMQ is chosen for its stability across the temperature range encountered in coffee brewing and steam production, and for its resistance to water, oils and cleaning chemicals used in daily maintenance.

Cleaning is limited to wiping the seating area before installation; the O-ring itself should not be exposed to abrasive pads or solvents that could degrade the silicone surface. Once installed, it requires no further upkeep beyond periodic inspection for wear or hardening.

This O-ring is a direct replacement part for the SCHAERER models listed in the compatibility tables. It is categorised under coffee-machine spares, specifically sealing components.