How to Measure O-Rings for the Petroleum, Oil, and Gas Industry

Dock on the bay at nightO-rings are solid doughnut-shaped seals made of various polymers such as nitrile rubber, silicone rubber, and fluorosilcone rubber. O-rings are designed to block the passage of gases and liquids between two mating surfaces. They are available in a wide variety of sizes and thicknesses for both standard and non-standard sealing applications (learn how to measure O-rings here).

The petroleum, oil, and gas industry relies heavily on O-rings in all facets of operations. They are needed for the equipment and products that are used in exploration, extraction, refining, and transportation. Because of this, the demand for O-rings is ever increasing. They are an indispensable component for much of the equipment used at oil fields, pumping stations, tanks, vessels, and refineries.

Petroleum products are used to propel vehicles, heat buildings, and produce electricity. In the United States alone the consumption of energy from petroleum is used more than any other energy source. The equivalent of about 37% of all the energy consumed in the United States is petroleum based, which is approximately 19.7 million barrels of oil per day. Gasoline is the most consumed petroleum product in the United States. In 2016, motor gasoline consumption averaged about 391 million gallons per day, the largest amount recorded and equal to about 47% of total U.S. petroleum consumption. In addition, petroleum is also a raw material used to make such products as plastics, polyurethane, solvents, and hundreds of other intermediate and end-user goods. Throughout the entire delivery chain, O-rings are a critical component used to preserve the integrity of the delivery system. The highest quality of O-rings is required to ensure safety and reliability and to meet environmental standards and protections.

Manufacturer’s Rubber & Supply has one of the largest inventories of O-rings and O-ring products of the highest quality available. Our O-ring sizing chart assists our customers and clients to select the right size O-ring to meet their sealing requirements (refer here to the O-ring size chart).

O-ring manufacturers in the United States adhere to the industry standard size as defined by Aerospace Standard AS568A, Aerospace Size Standard for O-rings. The AS568A categorizes O-rings sizes in six groups measured in inches and millimeters. Five of the six groups, or series, are based on cross-sectional diameter. The other series features 20 sizes for boss seals. Knowing the cross-sectional diameter and either the inside or outside diameter is necessary to determine the correct size O-ring for an application.

In the petroleum, oil, and gas industry, material of the O-ring is a critical factor when selecting one. Most likely the equipment will have specs that list the O-ring size and requirements. If the specs are not available, O-ring size is determined by measuring inside diameter, outside diameter and thickness or cross-sectional width, in metric or standard units. A Parker size cone is a pretty handy device used for measuring O-rings. Drop the O-ring over the tip of the cone and it measures dash sized (AS568) O-ring at a glance. However, measuring can also be done the old fashioned way with a ruler. Place an O-ring on a flat, level surface. Lay the ruler across the O-ring to measure the distance in millimeters from one outside edge to another. Determine the inside diameter by measuring the O-ring from inside edge to inside edge. Use a vernier caliper to measure the thickness.

With expanding oil and gas exploration and extraction worldwide, sealing solutions are needed to meet the challenges throughout the oil and gas supply and delivery chain. These challenges include some of the most unforgiving environments in the world utilizing some of the harshest chemicals and gases. The operational integrity and need of high-performance seals have never been greater. When ordering O-rings, be sure to know the size and the application requirements, or contact Manufacturer’s Rubber & Supply representative who will gladly assist you.

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