O-rings are an essential part of the industrial industry. They are designed to stop leakage where fluids are transferred, and where chances of leakage are high. O-rings may be in place along rotating shafts, sleeves, placed in flange grooves, valve bonnets, or any threaded or bolted connection. They are usually put into a groove to hold them in place and then squeezed between two surfaces. At first look, the concept of O-rings looks extremely simple. However, the correct size, material, and design will determine the type of O-ring needed for the correct job.

Like the name implies, O-rings have a circular shape and their size will be determined by what is needed to be sealed. O-rings are sized by the inside diameter (I.D.) then by the cross section (C/S) or width (W). There will be instances where O-rings cant be made exactly to the dimensions needed, so manufactures are allowed to make them within range of their original dimensions.  They are also made using a variety of materials that include Viton, EPDM, Silicon, PTFE, FKM, FFKM, Buna-N, Nitrile, and Kalrez. Most O-rings are molded from rubber, silicone, or a blend like Flourosilicone. Molded rubbers are made of “compounds” which essentially means it is a blend of materials. Keep in mind that temperature range, application, what is being sealed, pressure being sealed, the size, and speed will determine what type of O-ring you will need.

O-rings that have cheap fillers will often show premature cracking when in service, so it’s essential to be able to identify which O-ring right for you. With all variables that take into play of choosing the correct O-ring, American Seal & Packing can advise on which O-ring will provide the best probability for a successful seal. An O-ring’s designed will vary from each industry and application, but you can assure that American Seal & Packing will help choose the correct O-ring which will bring long term sealing success.