An o-ring is a circular component made from either rubber or plastic. It is used for the purpose of sealing off part of a piece of equipment, similar to a gasket. O-rings can come in various configurations depending on the application or industry. Metric o-rings, in particular, are a type of o-ring whose thickness is measured using the metric system. This makes them compatible with equipment made in countries that use the metric system for measurement. Therefore, most manufacturers of o-rings offer models measured with both the Imperial and metric systems.
Quick links to Metric O-Rings Information
Applications of Metric O-Rings
O-rings are used for numerous applications, including hydraulic valves, pumps, and pneumatic systems. Industries that use o-rings in their facilities include water treatment, chemical processing, oil refineries, aviation, and aerospace. Many manufacturers provide o-ring kits, which is a group of o-rings of assorted types and sizes, to accommodate for industries that utilize various types of machinery.
Each material that is used to make an o-ring is recommended for particular applications. Teflon and Viton o-rings are valued for their resistance to the elements, high temperatures, and various chemicals, and are thus used in numerous outdoor applications. Silicone o-rings are commonly used in the medical field and in hot air applications because of their thermal stability. Metal o-rings are much more resistant to corrosion, pressure, and extreme temperatures than those made from elastomers, and are thus used for sealing applications as well as numerous other industrial purposes.
How Metric O-Rings Work
The primary function of an o-ring is a sealant. During the assembly of a machine, an o-ring is placed between two or more parts to prevent liquids or gases from passing through when the machine or system is in use. When an o-ring is used as a sealant between a set of tubes or pipes, it is known as an o-ring seal. O-rings are one of the most valuable types of sealants currently available and one of the most crucial components for machine design because their flexible structures allow manufacturers to adjust them so they can precisely fit the measurements of the desired piece of equipment. Flat o-rings and large o-rings are primarily used for more specialized machines, so they are often customized. Since most of the world utilizes the metric system, customizable metric o-rings give American manufacturers the ability to significantly broaden their market.
Metric O-Ring Design and Customization
O-rings are made from materials that allow them to be used for a wide range of industries and applications. Rubber and elastomer materials include Viton, Teflon, and silicone. O-rings can also be made from metals such as gold, steel alloys, nickel, aluminum, copper, and silver. In some varieties of o-rings, metal alloys or plastic alloys are used as fillers for o-rings that are rubber or plastic-based. When o-rings have multiple layers of various materials (such as a plastic o-ring with a metal filler), the levels of strength and corrosion resistance can greatly increase. In addition, plastic o-rings with a metal filler can assist in sparks or electrical arcing. The material of the o-ring depends largely on the cost, the size, lubrication requirements, temperature, chemical compatibility, and the sealing pressure of the machinery. O-rings can vary greatly in price due to how many materials from which they can be made.
Factors to Consider When Purchasing Metric O-Rings
In addition to material, another important factor to keep in mind when searching for the right o-rings is quality. It is imperative to select the highest possible quality because of how important a role o-rings play in the assembly of a machine. If an o-ring is of poor quality, it will be unable to withstand prolonged intense use and will wear down much more quickly. In some cases, such as in the aerospace and aviation industry, faulty o-rings can cause important equipment to fail and significantly endanger those who are involved in operating them. The Challenger disaster of 1986 was caused by a gas leak because a rubber o-ring became rigid and failed to expand due to unseasonably cold outside temperatures. Although the repercussions of using poor-quality o-rings do not always pose a safety risk to workers, poor quality o-rings can cause a multitude of other problems, such as broken pipes, leaks, or flooding, leading to thousands of dollars in damage costs.
Fortunately, it is not difficult to identify a quality o-ring. Manufacturers of o-rings provide certifications or warranties on the products they offer. Furthermore, you can look for products that indicate that they are made in the USA, and are ISO certified. Doing extra research on the quality of the products will save you time and money in the long-term.