GASKETS, O-RINGS/KITS/O-CORDS, PACKINGS, and SEALS
DURABLA Compressed Gasket Materials, Made in Canada
Durlon® 7900/7925/7950
Economical Durlon Solutions
Durlon 7900 (off white), 7925 (light green) and 7950 (blue) are our economy grade aramid fiber and NBR general-purpose gasketing materials specifically engineered to deliver unsurpassed sealability, temperature resistance, and bolt torque retention when service ranges and applications are not severe.
Durlon 8300 is our premium grade, multi-service high strength carbon and NBR gasket sheet, designed to handle the extremes of pressure and temperature. As with all of our premium products, the versatility of this sheet enables the end user to standardize on one sheet for a multitude of applications and avoid the confusion of having to choose from several different sheets.
Specifically designed for applications commonly found in the power generation and chemical processing industries, the Durlon 8300 maintains excellent sealability during thermal cycling even in steam, hot oil, aliphatic hydrocarbons, natural gas, gasoline, solvents, inert gases, mild alkalis and acids.
Durlon 8400 (gold) is our outstanding next generation material that provides the widest range of chemical resistance of any compressed non-asbestos material available today. It's designed for high pH applications in the demanding services found in the pulp & paper, chemical processing and power generation industries where traditional compressed gasket materials have fallen short.
Durlon 8500 (green), our general-purpose "workhorse" material contains our unique blend of high strength aramid and inorganic fibers providing excellent results in steam, hydrocarbons, and new generation refrigerants. Durlon 8500 passed a modified API 607 fire test at an independent laboratory and has proven to be reliable in situations where temperature and pressure cycling causes failures of lesser quality materials.
Durlon 8600 (white), is an outstanding gasket material containing our unique blend of high strength aramid and inorganic fibers providing excellent sealability in steam, condensate, and dilute acids and where a "white" gasket material or an SBR binder is required.
Durlon 8700 (blue), is our premium neoprene (CR) gasket sheet combined with our unique blend of high strength aramid and inorganic fibers providing excellent sealability in services such as ammonia containing refrigerant systems.
Durlon® 7900/7925/7950
Economical Durlon Solutions
Durlon 7900 (off white), 7925 (light green) and 7950 (blue) are our economy grade aramid fiber and NBR general-purpose gasketing materials specifically engineered to deliver unsurpassed sealability, temperature resistance, and bolt torque retention when service ranges and applications are not severe.
Durlon 8300 is our premium grade, multi-service high strength carbon and NBR gasket sheet, designed to handle the extremes of pressure and temperature. As with all of our premium products, the versatility of this sheet enables the end user to standardize on one sheet for a multitude of applications and avoid the confusion of having to choose from several different sheets.
Specifically designed for applications commonly found in the power generation and chemical processing industries, the Durlon 8300 maintains excellent sealability during thermal cycling even in steam, hot oil, aliphatic hydrocarbons, natural gas, gasoline, solvents, inert gases, mild alkalis and acids.
Durlon 8400 (gold) is our outstanding next generation material that provides the widest range of chemical resistance of any compressed non-asbestos material available today. It's designed for high pH applications in the demanding services found in the pulp & paper, chemical processing and power generation industries where traditional compressed gasket materials have fallen short.
Durlon 8500 (green), our general-purpose "workhorse" material contains our unique blend of high strength aramid and inorganic fibers providing excellent results in steam, hydrocarbons, and new generation refrigerants. Durlon 8500 passed a modified API 607 fire test at an independent laboratory and has proven to be reliable in situations where temperature and pressure cycling causes failures of lesser quality materials.
Durlon 8600 (white), is an outstanding gasket material containing our unique blend of high strength aramid and inorganic fibers providing excellent sealability in steam, condensate, and dilute acids and where a "white" gasket material or an SBR binder is required.
Durlon 8700 (blue), is our premium neoprene (CR) gasket sheet combined with our unique blend of high strength aramid and inorganic fibers providing excellent sealability in services such as ammonia containing refrigerant systems.
JM CLIPPER (USA) gaskets come in three styles described below which are equivalent to Garlock, Chesterton, James Walker, etc.
Gasket Style 978-C
Description: this gasket is a dense, aramid/inorganic fiber reinforced, compressed, NBR sheet with a special, high temperature, anti-stick parting agent applied to both sides. It's high strength and excellent resistance to hot creep and broad chemical resistance make it an ideal high performance gasket material.
Application: gasket style 978-C can be used for gasketing in piping, machinery, or equipment containing steam, petroleum based liquids, gases and mild acids or alkalines. It may also be used in most solvents excluding MEK and high aromatics. Gasket style 978-C also has excellent sealability in ethylene glycol coolants and silicone fluids.
Gasket Style 1078
Description: gasket style 1078 WHITERILE is an off-white, compressed, NBR/synthetic fiber sheet that is recommended for service where color contamination is a concern. It is also a good choice for cutting intricate gaskets requiring especially clean cuts. With a high temperature parting agent as a standard surface treatment, 1078 is an excellent choice for general service gaskets.
Application: gasket style 1078 is recommended for use on process piping and equipment and all types of machinery. It can be used in mild acids and alkalis, water, steam, gasses, oils and gasoline, It can be used in most solvents excluding MEK and high aromatics. Gasket style 1078 also has excellent sealability in ethylene glycol coolants and silicone fluids.
Gasket Style NA-60
Gasket NA-60 is a low cost, NBR/aramid fiber, compressed gasket sheet made with all the great features of premium gasket materials without the cost. Only the best raw materials are used, without compromise. Gasket NA-60 is recommended for general service gaskets on all machinery, process piping and equipment. It offers broad chemical resistance, cutability, flexibility and is low in cost.
Over many decades,JM Clipper has developed its manufacturing process and customer service philosophy to provide value-added, high-quality sealing components to the most demanding specifications.
A HERITAGE OF INNOVATIONAs a division of Johns Manville until 1989, JM Clipper has manufactured specialty sealing components since the 1870s. The JM Clipper name began with the highly successful Clipper Oil Seal developed to control oil leaks on the Pan Am Clipper aircraft flying the Pacific in the 1930s.
Advertisements indicate the company was manufacturing "steam packing" as early as 1871 and gasket materials in 1891. During the early 1900s, the company specialized in rope, pump packing, and industrial textiles. By the 1930s, compressed gasket sheet and molded rubber reciprocating seals were added. Firmly established in rubber processing, JM Clipper then developed the Clipper Oil Seal which grew into today's full line of radial oil seals.
THE COMPANY TODAY JM Clipper offers a broad line of radial seals include Clipper Oil Seals, Split Seals, High and Medium Pressure Seals, Clipper SlipTiteT High-Performance Seals, Millennium Metallic Bearing Isolators and ProTechT Labyrinth Seals.
Today, JM Clipper's dedicated sales force and 2,000 independent distributors worldwide service 500 original equipment manufacturers (OEMs) and many thousands of industrial plants. Key markets include heavy equipment, aerospace, marine, oilfield, refining, chemical, mining, power generation, pulp and paper, primary metals, and other heavy industrial markets.
TECHNOLOGY LEADERSHIP JM Clipper meets customer needs with a wide range of new and proven technologies. These include close-tolerance machined PTFE, flexible graphite, unique rubber/fiber composites as well as more traditional rubber, plastic, and textile products. These materials are all utilized at the company's 205,000 square-foot facility in Nacogdoches, Texas, which opened in the mid-1980s.
The Redmond Plastics plant in Marion, New York, molds and machines filled and virgin PTFE, PEEKT, and RytonT on the most modern CNC machines. This facility is equipped to respond to EDI, bar code, quality, and certification requirements.
ISO-9001 CERTIFICATIONIn 1994, Det Norske Veritas Industries of the Netherlands completed its ISO audit and JM Clipper gained ISO-9001 certification for manufacturing, product design, and engineering which adds yet a higher level of quality assurance.
Gasket Style 978-C
Description: this gasket is a dense, aramid/inorganic fiber reinforced, compressed, NBR sheet with a special, high temperature, anti-stick parting agent applied to both sides. It's high strength and excellent resistance to hot creep and broad chemical resistance make it an ideal high performance gasket material.
Application: gasket style 978-C can be used for gasketing in piping, machinery, or equipment containing steam, petroleum based liquids, gases and mild acids or alkalines. It may also be used in most solvents excluding MEK and high aromatics. Gasket style 978-C also has excellent sealability in ethylene glycol coolants and silicone fluids.
Gasket Style 1078
Description: gasket style 1078 WHITERILE is an off-white, compressed, NBR/synthetic fiber sheet that is recommended for service where color contamination is a concern. It is also a good choice for cutting intricate gaskets requiring especially clean cuts. With a high temperature parting agent as a standard surface treatment, 1078 is an excellent choice for general service gaskets.
Application: gasket style 1078 is recommended for use on process piping and equipment and all types of machinery. It can be used in mild acids and alkalis, water, steam, gasses, oils and gasoline, It can be used in most solvents excluding MEK and high aromatics. Gasket style 1078 also has excellent sealability in ethylene glycol coolants and silicone fluids.
Gasket Style NA-60
Gasket NA-60 is a low cost, NBR/aramid fiber, compressed gasket sheet made with all the great features of premium gasket materials without the cost. Only the best raw materials are used, without compromise. Gasket NA-60 is recommended for general service gaskets on all machinery, process piping and equipment. It offers broad chemical resistance, cutability, flexibility and is low in cost.
Over many decades,JM Clipper has developed its manufacturing process and customer service philosophy to provide value-added, high-quality sealing components to the most demanding specifications.
A HERITAGE OF INNOVATIONAs a division of Johns Manville until 1989, JM Clipper has manufactured specialty sealing components since the 1870s. The JM Clipper name began with the highly successful Clipper Oil Seal developed to control oil leaks on the Pan Am Clipper aircraft flying the Pacific in the 1930s.
Advertisements indicate the company was manufacturing "steam packing" as early as 1871 and gasket materials in 1891. During the early 1900s, the company specialized in rope, pump packing, and industrial textiles. By the 1930s, compressed gasket sheet and molded rubber reciprocating seals were added. Firmly established in rubber processing, JM Clipper then developed the Clipper Oil Seal which grew into today's full line of radial oil seals.
THE COMPANY TODAY JM Clipper offers a broad line of radial seals include Clipper Oil Seals, Split Seals, High and Medium Pressure Seals, Clipper SlipTiteT High-Performance Seals, Millennium Metallic Bearing Isolators and ProTechT Labyrinth Seals.
Today, JM Clipper's dedicated sales force and 2,000 independent distributors worldwide service 500 original equipment manufacturers (OEMs) and many thousands of industrial plants. Key markets include heavy equipment, aerospace, marine, oilfield, refining, chemical, mining, power generation, pulp and paper, primary metals, and other heavy industrial markets.
TECHNOLOGY LEADERSHIP JM Clipper meets customer needs with a wide range of new and proven technologies. These include close-tolerance machined PTFE, flexible graphite, unique rubber/fiber composites as well as more traditional rubber, plastic, and textile products. These materials are all utilized at the company's 205,000 square-foot facility in Nacogdoches, Texas, which opened in the mid-1980s.
The Redmond Plastics plant in Marion, New York, molds and machines filled and virgin PTFE, PEEKT, and RytonT on the most modern CNC machines. This facility is equipped to respond to EDI, bar code, quality, and certification requirements.
ISO-9001 CERTIFICATIONIn 1994, Det Norske Veritas Industries of the Netherlands completed its ISO audit and JM Clipper gained ISO-9001 certification for manufacturing, product design, and engineering which adds yet a higher level of quality assurance.
HYDRAULIC AND PNEUMATIC SEALS, Sakagami brand from Japan
Chevron Vee Packing
Rod seals- Single- and double-acting
Materials: fluoroplastic, polyurethane or rubber
Piston seals- Single- and double-acting
Materials: fluoroplastic, polyurethane or rubber
Dust/Wiper seals- Single- and double-acting
Materials: fluoroplastic, polyurethane or rubber
Rotor seals-Seals for rotary and pivoting movements Materials: fluoroplastic,
polyurethane, PTFE compoundStatic seals
Back up ring
Buffer ring
Wear ring- Material: Laminate ,PTFE / bronze compound
Chevron Vee Packing
Rod seals- Single- and double-acting
Materials: fluoroplastic, polyurethane or rubber
Piston seals- Single- and double-acting
Materials: fluoroplastic, polyurethane or rubber
Dust/Wiper seals- Single- and double-acting
Materials: fluoroplastic, polyurethane or rubber
Rotor seals-Seals for rotary and pivoting movements Materials: fluoroplastic,
polyurethane, PTFE compoundStatic seals
Back up ring
Buffer ring
Wear ring- Material: Laminate ,PTFE / bronze compound
JM CLIPPER AND ROBCO COMPRESSED MECHANICAL PACKINGS (MADE IN USA/CANADA)
High Compression packing is an important part of ensuring that your sensitive machine parts work together the way that they are supposed to without any leaks. Another name for compression packing is mechanical packing. For machines in which compression packing is used, a seal is created by packing down the material and creating compression so that everything is tightly held inside the machine without leaks.
Compression packing is commonly used in various industries like the pulp and paper industry, petrochemicals, steel mills, and pharmaceutical industry. It is also commonly used in utilities service industries like water and sewage plants. Companies decide to use compression packing for various kinds of liquids and gasses, like acids, solvents, and even oil and petroleum. Mechanical packing is technically a form of compression packing that is used to seal mixers, agitators, pumps, and other types of mechanical equipment.
Different types of compression packing offer different specifications, so it is very important to understand exactly what you are sending before you plan on which type of compression packing you need. For example, some types of compression packing only hold up to 500 psi of pressure, while others can hold up to 300 psi for some types of packages and up to 2,000 psi in others. It all depends on exactly what kind of machine you are operating and what kind of pressurized packing is needed in order to keep it in good working order.
There are many different types of materials used in compression packing, and knowing exactly what is in the machine and the components it processes is the most important part of choosing the right kind of material. In order to help choose the right material, manufacturers consider the shaft speed, temperature, the medium that will be sealed, and the amount of pressure that is required in order to keep it in top shape.
Some of the most common options in compression packing include graphite packing, lantern ring coils, carbon packing, braided compression packing, flexible shock resistant packing, and more. Before choosing a material, be sure to ask about the specifications for that type of material so that you know that it will be exactly what you need.
High Compression packing is an important part of ensuring that your sensitive machine parts work together the way that they are supposed to without any leaks. Another name for compression packing is mechanical packing. For machines in which compression packing is used, a seal is created by packing down the material and creating compression so that everything is tightly held inside the machine without leaks.
Compression packing is commonly used in various industries like the pulp and paper industry, petrochemicals, steel mills, and pharmaceutical industry. It is also commonly used in utilities service industries like water and sewage plants. Companies decide to use compression packing for various kinds of liquids and gasses, like acids, solvents, and even oil and petroleum. Mechanical packing is technically a form of compression packing that is used to seal mixers, agitators, pumps, and other types of mechanical equipment.
Different types of compression packing offer different specifications, so it is very important to understand exactly what you are sending before you plan on which type of compression packing you need. For example, some types of compression packing only hold up to 500 psi of pressure, while others can hold up to 300 psi for some types of packages and up to 2,000 psi in others. It all depends on exactly what kind of machine you are operating and what kind of pressurized packing is needed in order to keep it in good working order.
There are many different types of materials used in compression packing, and knowing exactly what is in the machine and the components it processes is the most important part of choosing the right kind of material. In order to help choose the right material, manufacturers consider the shaft speed, temperature, the medium that will be sealed, and the amount of pressure that is required in order to keep it in top shape.
Some of the most common options in compression packing include graphite packing, lantern ring coils, carbon packing, braided compression packing, flexible shock resistant packing, and more. Before choosing a material, be sure to ask about the specifications for that type of material so that you know that it will be exactly what you need.
MECHANICAL SHAFT SEALS , FB (Japan) and Robco (Canada) brands
As most engineers know, a successful seal must be designed to give long life, reduce maintenance and provide automatic self-adjustment. The seals in our line meet these basic requirements. In addition, they offer other important advantages to the seal user.
As most engineers know, a successful seal must be designed to give long life, reduce maintenance and provide automatic self-adjustment. The seals in our line meet these basic requirements. In addition, they offer other important advantages to the seal user.
- ABSOLUTE SEALING. Resulting in less pumpage loss, cleaner facility environment, reduced fire hazard, no danger from fumes and no contamination of the fluid being handled.
- NO RUBBING FRICTION BETWEEN SHAFT AND SEAL PARTS. Eliminate expensive shaft and sleeve replacement by replacing your old packing with our new state-of-the-art mechanical seals.
- GREATER FLEXIBILITY OF SEALS MEANS LONGER SERVICE LIFE. Seals have more flexibility than packing and are able to compensate for shaft whip, axial and radial end play, as well as vibration and wear of the sealing faces.
- LESS FRICTION MEANS VALUABLE POWER SAVINGS. Seals create less friction than packing and therefore require less horsepower.
- PRECISION LAPPED SEALING SURFACES. Positively control leakage and eliminate "break in" runs.
- HIGHER SPEEDS AND PRESSURES ARE NOT A PROBLEM.
- POSITIVELY DRIVEN MECHANICAL SEALS.
- EXTREME FLAT SURFACES OF MATING FACES. Care is taken to furnish precision lapped sealing surfaces with a flatness within three light bands maintaining the necessary face film lubrication.
- MATERIALS OF CONSTRUCTION. TFE, AFLAS®, EPR and VITON®materials are available for those applications where NEOPRENE and BUNA are not compatible with the process fluid. Metal parts are normally made of brass, plated steel or stainless steel, but other alloys, such as Monel® or Hastelloy® can be supplied. Seat materials are available in a wide selection.
OIL SEALS OR GREASE SEALS for all applications and industries
Oil seals - often called grease, fluid or dirt seals - close spaces between stationary and moving components in mechanical equipment, helping prevent lubricant escape. They also stop harmful contaminants from entering machinery, particularly in severe environments. Vital components of practically every type of machine and vehicle in operation, oil seals protect all types of precision-constructed, close-fitting ball, sleeve and roller bearings.
In precision bearings, oil seals help prevent lubricants from escaping the bearings or a specific area. In machine components, oil seals help prevent abrasives, corrosive moisture and other harmful contaminants from entering machinery. They also help stop inter mixture of two different mediums, such as lubricating oil and water.
Design Attributes
Oil and grease seals supplied by us feature precision sealing designs that are matched to many original equipment or aftermarket applications. The seals help ensure consistent and reliable performance.
Applications
The seals are used in a full range of equipment in thousands of applications, such as
Automotive
Manufacturing
Off-highway
Oil refineries
Power transmission
Usage
In a typical application, the oil seal is installed adjacent to a bearing, sealing in or sealing out, as necessary, the various liquids, gases or solids encountered by the particular mechanism.
Materials or compounds
Oil and grease seals are available in the following compounds: felt, leather, urethane, nitrile, polyacrylate, ethylene-acrylic or polyacrylic (Vamac ), silicone, fluoro-elastomer, tetrafluoro-ethylene propylene (Aflas ) and PTFE.
Note: A seal's operating environment should be determined before selecting the sealing element or lip material.
Sizes
Our automotive and industrial seals are available in small-bore to large sizes, as well as in metric and high-temperature varieties.
Our brands include ,but are not limited to NATIONAL, JM CLIPPER, NOK, GARLOCK, STEMCO, CR, MUSASHI, FOS, TTO, KOK, etc.
We cater to the global marketplace as we export and ship worldwide while we entertain retail, end-users, wholesale, resellers, dealers, distributors, and OEMs clients.
Made to order oil seals are also accepted.
Oil seals - often called grease, fluid or dirt seals - close spaces between stationary and moving components in mechanical equipment, helping prevent lubricant escape. They also stop harmful contaminants from entering machinery, particularly in severe environments. Vital components of practically every type of machine and vehicle in operation, oil seals protect all types of precision-constructed, close-fitting ball, sleeve and roller bearings.
In precision bearings, oil seals help prevent lubricants from escaping the bearings or a specific area. In machine components, oil seals help prevent abrasives, corrosive moisture and other harmful contaminants from entering machinery. They also help stop inter mixture of two different mediums, such as lubricating oil and water.
Design Attributes
Oil and grease seals supplied by us feature precision sealing designs that are matched to many original equipment or aftermarket applications. The seals help ensure consistent and reliable performance.
Applications
The seals are used in a full range of equipment in thousands of applications, such as
Automotive
Manufacturing
Off-highway
Oil refineries
Power transmission
Usage
In a typical application, the oil seal is installed adjacent to a bearing, sealing in or sealing out, as necessary, the various liquids, gases or solids encountered by the particular mechanism.
Materials or compounds
Oil and grease seals are available in the following compounds: felt, leather, urethane, nitrile, polyacrylate, ethylene-acrylic or polyacrylic (Vamac ), silicone, fluoro-elastomer, tetrafluoro-ethylene propylene (Aflas ) and PTFE.
Note: A seal's operating environment should be determined before selecting the sealing element or lip material.
Sizes
Our automotive and industrial seals are available in small-bore to large sizes, as well as in metric and high-temperature varieties.
Our brands include ,but are not limited to NATIONAL, JM CLIPPER, NOK, GARLOCK, STEMCO, CR, MUSASHI, FOS, TTO, KOK, etc.
We cater to the global marketplace as we export and ship worldwide while we entertain retail, end-users, wholesale, resellers, dealers, distributors, and OEMs clients.
Made to order oil seals are also accepted.
O-RINGS, O-RING KITS AND O-CORDS made of Buna-N, Silicone, Viton and Teflon materials. Brands include National, JM Clipper, and ROBCO of USA/Canada.
An O-ring, also known as a packing, or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.
The O-ring may be used in static applications or in dynamic applications where there is relative motion between the parts and the O-ring. Dynamic examples include rotating pump shafts and hydraulic cylinder pistons.
O-rings are one of the most common seals used in machine design because they are inexpensive, easy to make, reliable, and have simple mounting requirements. They can seal tens of megapascals (thousands of psi) of pressure.
O-rings are one of the simplest, yet most engineered, precise, and useful seal designs ever developed. They are one of the most common and important elements of machine design. O-rings are available in various metric and inch standard sizes. Sizes are specified by the inside diameter and the cross section diameter (thickness). In the US the most common standard inch sizes are per SAE AS568C specification (e.g. AS568-214). ISO 3601-1:2008 contains the most commonly used standard sizes, both inch and metric, worldwide. The UK also has standards sizes known as BS sizes, typically ranging from BS001 to BS932. Several other size specifications also exist.
Typical applications
Successful O-ring joint design requires a rigid mechanical mounting that applies a predictable deformation to the O-ring. This introduces a calculated mechanical stress at the O-ring contacting surfaces. As long as the pressure of the fluid being contained does not exceed the contact stress of the O-ring, leaking cannot occur. Fortunately, the pressure of the contained fluid transfers through the essentially incompressible O-ring material, and the contact stress rises with increasing pressure. For this reason, an O-ring can easily seal high pressure as long as it does not fail mechanically. The most common failure is extrusion through the mating parts.
The seal is designed to have a point contact between the O-ring and sealing faces. This allows a high local stress, able to contain high pressure, without exceeding the yield stress of the O-ring body. The flexible nature of O-ring materials accommodates imperfections in the mounting parts. But it is still important to maintain good surface finish of those mating parts, especially at low temperatures where the seal rubber reaches its glass transition temperature and becomes increasingly crystalline. Surface finish is also especially important in dynamic applications. A surface finish that is too rough will abrade the surface of the O-ring, and a surface that is too smooth will not allow the seal to be adequately lubricated by a fluid film.
Vacuum applications
In vacuum applications, the permeability of the material makes point contacts quite useless. Instead, higher mounting forces are used and the ring fills the whole groove. Also, round back-up rings are used to save the ring from excessive deformation. Because the ring feels the ambient pressure and the partial pressure of gases only at the seal, their gradients will be steep near the seal and shallow in the bulk (opposite to the gradient of the contact stress [8] See: Vacuum_flange#KF.2FQF. High-vacuum systems below 10−9 Torr use copper or nickel O-rings. Also, vacuum systems that have to be immersed in liquid nitrogen use indium O-rings, because rubber becomes hard and brittle at low temperatures.
High temperature applications
In some high-temperature applications, O-rings may need to be mounted in a tangentially compressed state, to compensate for the Gow-Joule effect.
An O-ring, also known as a packing, or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.
The O-ring may be used in static applications or in dynamic applications where there is relative motion between the parts and the O-ring. Dynamic examples include rotating pump shafts and hydraulic cylinder pistons.
O-rings are one of the most common seals used in machine design because they are inexpensive, easy to make, reliable, and have simple mounting requirements. They can seal tens of megapascals (thousands of psi) of pressure.
O-rings are one of the simplest, yet most engineered, precise, and useful seal designs ever developed. They are one of the most common and important elements of machine design. O-rings are available in various metric and inch standard sizes. Sizes are specified by the inside diameter and the cross section diameter (thickness). In the US the most common standard inch sizes are per SAE AS568C specification (e.g. AS568-214). ISO 3601-1:2008 contains the most commonly used standard sizes, both inch and metric, worldwide. The UK also has standards sizes known as BS sizes, typically ranging from BS001 to BS932. Several other size specifications also exist.
Typical applications
Successful O-ring joint design requires a rigid mechanical mounting that applies a predictable deformation to the O-ring. This introduces a calculated mechanical stress at the O-ring contacting surfaces. As long as the pressure of the fluid being contained does not exceed the contact stress of the O-ring, leaking cannot occur. Fortunately, the pressure of the contained fluid transfers through the essentially incompressible O-ring material, and the contact stress rises with increasing pressure. For this reason, an O-ring can easily seal high pressure as long as it does not fail mechanically. The most common failure is extrusion through the mating parts.
The seal is designed to have a point contact between the O-ring and sealing faces. This allows a high local stress, able to contain high pressure, without exceeding the yield stress of the O-ring body. The flexible nature of O-ring materials accommodates imperfections in the mounting parts. But it is still important to maintain good surface finish of those mating parts, especially at low temperatures where the seal rubber reaches its glass transition temperature and becomes increasingly crystalline. Surface finish is also especially important in dynamic applications. A surface finish that is too rough will abrade the surface of the O-ring, and a surface that is too smooth will not allow the seal to be adequately lubricated by a fluid film.
Vacuum applications
In vacuum applications, the permeability of the material makes point contacts quite useless. Instead, higher mounting forces are used and the ring fills the whole groove. Also, round back-up rings are used to save the ring from excessive deformation. Because the ring feels the ambient pressure and the partial pressure of gases only at the seal, their gradients will be steep near the seal and shallow in the bulk (opposite to the gradient of the contact stress [8] See: Vacuum_flange#KF.2FQF. High-vacuum systems below 10−9 Torr use copper or nickel O-rings. Also, vacuum systems that have to be immersed in liquid nitrogen use indium O-rings, because rubber becomes hard and brittle at low temperatures.
High temperature applications
In some high-temperature applications, O-rings may need to be mounted in a tangentially compressed state, to compensate for the Gow-Joule effect.
