O-rings

O-rings are solid-rubber seals that are shaped like a doughnut. When pressed between two mating surfaces, O-rings block the passage of liquids or gases. O-rings can form a static or dynamic seals. A static seal is where the O-ring does not move and is used simply for containing pressure or maintaining a vacuum. Dynamic seals can be reciprocating (like a piston and cylinder), or rotating (shaft rotating in a housing).  Axial squeeze and radial squeeze are two methods for applying an O-ring. An axial squeeze is when the ring is compressed parallel to a line drawn through the center or axis of the ring. In a radial squeeze the ring is compressed between the internal diameter (ID) and overall diameter (OD).  Also, a boss seal is an O-ring, however it just doesn't fit the standard sizes for an O-ring. A boss is a cylindrical projection on a casting or forging. The end of that projection is machined to provide a flat, smooth surface for sealing. Straight threads used with O-rings provide a better seal than tapered threads used alone.

Pages: 1 - 2 of 2