The sinuses are air-filled cavities. 1  They are located: 2  Within the bony structure of the cheeks. 3  Behind the forehead and eyebrows. 4  On either side of the bridge of the nose. 5  Behind the nose directly in front of the brain.
An O-ring is a round ring that is used as a gasket for sealing a connection. O-rings are typically constructed out of polyurethane, silicone, neoprene, nitrile rubber or fluorocarbon. These rings are commonly used in mechanical applications, such as pipe connections, and help to ensure a tight seal between two objects. O-rings are designed to be seated in a groove or housing that keeps the ring in place. Once in its track, the ring is compressed between the two pieces and, in turn, creates a strong seal where they meet.
O-Ring Face Seal (ORFS) SAE J5143. The best leak protection available today. The male fitting has a straight thread and O-ring in the face. The female has a straight thread and a machined flat face. The seal takes places by compressing the O-ring onto the flat face of the female, similar to a split flange fitting. The threads hold the connection mechanically. Click here to view Size Chart