An O-ring is a gasket in the form of a ring with a circular cross section. … When the two surfaces contact, they form a gland, and compress the O-ring, which deforms the round cross section. This diametrically squeezes the seal, and the resulting force ensures surface contact with the inner and outer walls of the gland.

How does ring sealing work?

O-rings seal by mechanical deformation that creates a barrier to a fluid’s potential leak path between two closely mated surfaces. O-rings are typically installed in a groove that’s machined or molded in one of the surfaces to be sealed.

How much pressure can an O-ring hold?

Most o-rings are designed to operate at pressures up to 1,500 psi. At higher pressures, the material must have enough strength to resist extruding into the clearance gap. The chart shows the recommended combined limits of clearance, gap, material hardness and system pressure differential.