The first U.S. patent for the o-ring was filed in 1937 by Niels Christensen. During WW2, the US government deemed it as a critical war-related item and therefore transferred the rights to manufacture it to many other organizations. Christensen received a payment because of this, but 20 years after his death, his heirs received another large payment due to litigation. With how important and commonly used o-rings are today, maybe the payments would be even bigger.
A gasket is a shaped ring that is used to seal the junction between two surfaces. Seals are used to prevent leaks and help join mechanisms together. An o-ring is a type of gasket that has a circular cross section and is designed to sit in a groove and compress during assembly between two or more parts, which creates a seal at the interface. An o-ring is used to seal connections in pipes, tubes, etc. They are common in machine design because they are inexpensive, easy to make, and have simple mounting requirements.
Design and the material used are dependent upon factors such as quality, cost, application temperature, sealing pressure, chemical compatibility, etc. In the transportation industry, chemical exposure, extreme temperatures, and vibration are common factors in deciding which o-ring to use. In the oil, gas, and industrial industries, o-rings need to withstand extreme temperatures, noxious chemicals, and high compression. Some of the common types of o-ring applications are for static axial seals, reciprocating dynamic seals, and rotary seals.
The first consideration in designing grooves for static axial seals is determining whether the pressure is inward or outward. For outward pressure, the outside diameter of the groove and the groove width for the inside diameter are important; for inward pressure, the inside diameter is important. In short stroke applications, within a dynamic reciprocating application, smaller diameter o-rings are useful; in longer strokes, a thicker cross-sectional o-ring is useful. There are many specialized o-ring compounds designed for rotary service. They are reliable under specific conditions.
Don’t forget that rubber products, such as o-rings and seals, have an expiration date. So, pay careful attention to this and get them regularly inspected or replaced.
At ASAP NSN Parts, owned and operated by ASAP Semiconductor, we can help you find all the o-rings you need, new or obsolete. As a premier supplier of parts for the aerospace, civil aviation, and defense industries, we’re always available and ready to help you find all the parts and equipment you need, 24/7x365. For a quick and competitive quote, email us at firstname.lastname@example.org or call us at 1-714-705-4780.