O-rings have an exceptionally versatile range of applications, from aircraft hydraulic systems to semiconductor processing to medical device seals. One extremely important category of o-ring applications is uses that involve water. The historical roots of the o-ring lie in plumbing applications, and today o-rings are used for sealing, filtering, transporting and even exploring water. Here’s a look at four common types of o-ring applications that involve water.
Plumbing
The relationship between o-rings and water traces back to the historical roots of the o-ring in the mid-19th century. At that time, water pipe counterbores employed gaskets made from cross-sectioned india rubber rings, which helped prevent leakage between pipe sections. Thomas Edison built on this to develop a design for a water faucet which used an o-ring prototype for gas sealing, which he patented in 1882, the same year he used a similar seal for a light bulb.
Today, o-rings continue to be used for pipe fittings and other plumbing applications. Many pipes are designed to be connected with an o-ring. Some pipe fittings even have internal o-rings built in which compress when a pipe is inserted in order to help hold the pipes together. O-rings are also used to seal faucets, toilet tanks and other types of water tanks. This has applications in both consumer and commercial plumbing. For instance, o-rings have been adapted to seal tubing and tanks in nuclear reactors, where preventing leakage is vital for both performance and safety.
Water Filters
O-rings also play an important role in water filter systems. For example, in whole house water filter systems, o-rings are used to seal off the filter’s housing unit. An improper seal on the o-ring can cause the housing to leak, degrade the water pressure of the system and allow bacteria to contaminate the water supply. Leaking can also cause water damage, which can be extremely expensive. Water filter housing caps must have o-rings sealed securely to water filter housing sumps to prevent leaks. O-rings must be properly lubricated to prevent swelling, which can disrupt sealing. They should be replaced after every two filter changes or whenever they look worn.
Water filters have other uses in homes as well. Shower heads use o-rings to form a tight seal. A leaky shower head is often a symptom of a worn o-ring that has become hardened or split. Fixing a leaky shower can be as simple as replacing an o-ring.
Pool filters also use several different types of o-rings. The one that wears out most often is the tank o-ring. This can damage pool filter systems if it becomes too worn, so it should be replaced each time the filter is cleaned or the cartridge or grid elements are replaced. O-rings are also used on pool pumps, heaters, valves and chlorinators.
Portable Water
O-rings are also used to carry portable water in containers such as hydration packs, water bottle, and tumblers. Sealing these types of containers with o-rings ensures that water does not spill. A good seal also maintains temperature so that water stays cool or other liquids stay warm.
For instance, the Camelbak line of backpacks combine water and gear storage into a single, handy portable pack which can be used to stay hydrated while engaged in activities such as running, cycling or attending music festivals. CamelBak containers are spill-proof and bacteria-proof, which requires a good o-ring seal. Maintaining a good seal on this type of product requires a very precise fit between the o-ring and its corresponding groove, to avoid running the risk of leaking or contamination. To ensure a correct fit for this and other applications, manufactures produce o-rings in a wide variety of sizes. For instance, seal manufacturer Apple Rubber has a catalog of over 7,000 o-ring sizes, and uses a tooling process that is continually adding more size options.
Scuba Diving
O-rings also play a vital role in another activity associated with water: scuba diving. O-rings are used on scuba tanks, valves, and regulators to ensure that air stays sealed as it travels between the tank and the diver’s mouth. Without a strong seal, air can leak out, shortening a dive or creating a dangerous situation. Scuba o-rings wear out regularly due to wear, tear and pressure.
This makes o-ring maintenance a crucial part of scuba diving. Divers frequently apply silicon-based lubricant to o-rings to keep them soft and free of cracks. O-rings should be replaced when they become discolored, hard or cracked. Most divers can learn to replace the o-ring on a regulator themselves, but other o-ring replacements should be left to professionals.
Plumbing, water filters, portable water transportation and scuba diving are four examples of how water figures into many common o-ring applications. By providing a reliable tight seal to contain fluids and regulate their flow, o-rings make it possible for us to enjoy running water, drink clean water, carry water anywhere and even explore deep beneath the surface of the water — all thanks to a tiny rubber seal originally invented to hold pipes together.
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