What Are Backup O-Rings and How Do They Work?


O-rings offer a simple and effective solution to protect against leaks. Also known as toric joints, they are commonly found in machines.

O-rings consist of a donut-shaped piece of elastomer that seals the mating surface between two parts. If the two parts have a hollow passage through gas or liquid flows, an O-ring may be required. For some sealing applications, though, a backup O-ring may be required as well.

The Basics of Backup O-Rings

Backup O-rings are designed to protect against leaks in the event that the main O-rings fail. All backup O-rings are used in conjunction with a main O-ring. They simply serve as a failsafe. If the main O-ring fails, the backup O-ring will ensure that fluid or gas doesn’t leak out of the machine with which it’s used.

You can use a backup O-ring as a secondary form of leak protection. It will add another level of protection to ensure that liquid or gas doesn’t leak out of the machine with which it’s used.

How Backup O-Rings Work

All O-rings feature a circular shape, and they are all made of an elastomer that’s able to withstand heat and pressure. Backup O-rings are no exception. The main difference is that backup O-rings will only be exposed to the liquid or gas flowing through the machine if the main O-ring fails.

Machines often contain liquid like coolant, oil or other lubricating fluids. Some of them contain gas as well, such as combustion gas. As liquid or gas travels through the various parts of a machine, it may leak out of the mating surface between the respective parts. In most cases, a single O-ring will suffice for each mating surface. It will withstand heat and pressure to prevent leaks from occurring.

Backup O-rings are placed behind the main O-ring. Each backup O-ring is used in conjunction with a separate main O-ring. The main O-ring is located directly around the mating surface of two parts. And behind the main O-ring is a backup O-ring. Even if the main O-ring fails, liquid or gas will remain contained. It won’t be able to breach the mating surface of the two parts due to the backup O-ring.

In Conclusion

For an added level of protection against leaks, you may want to use a backup O-ring. It will give you peace of mind knowing that if the main O-ring fails, the machine won’t leak liquid or gas. The backup O-ring will act as a secondary seal to protect against leaks.