Gaskets are mechanical components used to create seals at the point of connection between two pieces of equipment. In applications in which liquids or gasses are transmitted through pipes, hoses or tubing, gaskets prevent leaking and loss of pressure at connection points. Because so many industries make such wide use of so many chemicals under so many circumstances, an entire industry of connection management solutions designers has emerged to accommodate them.
Gasket design and manufacturing have contributed significantly to improve the efficiency and safety of all sorts of industrial products including machines, vehicles, and pipelines. A gasket provides a mechanical seal that fills the space between two or more joining surfaces to ensure a tight seal, usually to avoid any possible leakage to or from the objects. Some types of gaskets include Teflon, exhaust, neoprene, viton, rubber, head, silicone, high temperature, spiral wound, EPDM, metal and more. Most often, gaskets are made out of flat materials and each gasket is punched out of a sheet of material to be made. Rubber gaskets are often made by die cutting from flat rubber or metal sheets. The process of die cutting allows a manufacturer to have design flexibility. Many industries use gaskets a great deal including automotive, aerospace, transportation, aviation, military, plumbing systems, and appliances. Gaskets play a very important role in any system that uses them, especially when toxic chemicals or liquids are involved and a spill could place harm on surrounding people and the environment.
Gaskets range in their design from very simple to very complex, come is all shapes and sizes, and are used for many different sealing applications. The simplest type of gasket is the o-ring which is commonly made out of natural or synthetic rubber, is very thin and has an O-shape as its name suggests. Complex gaskets can be textured to fit more effectively in a connection point; such shaped gaskets can be tapered, ridged, grooved, or otherwise shaped to create a tight seal between two objects. Gaskets materials must always be specifically chosen with regard to the conditions in which the gaskets will be applied. Whatever the gasket configuration, each design is engineered to accommodate the conditions of a specific purpose, and the importance of anticipating all of those conditions cannot be overstated.
Innovations in gasket design and manufacturing have contributed significantly to improved safety and efficiency of all kinds of industrial products: vehicles, pumping equipment and pipelines are just a few examples. Of particular importance to the gasket manufacturing industry have been advancements in the field of synthetic rubber development. Gaskets materials must always be carefully chosen with regard to the conditions in which the gaskets will be applied. Viton gaskets, EPDM gaskets, neoprene gaskets, silicone gaskets and other synthetic rubber gaskets each offer different qualities of tensile strength, heat resistance, non-reactivity, corrosion resistance, extreme temperature performance and chemical compatibility. In addition to the increasing availability of new gasketing materials, innovative gasket configurations have given professionals control over the most demanding and irregular connections. Spiral wound gaskets, high temperature gaskets, jacketed gaskets, Teflon gaskets and other special configurations allow for the creation of reliable seals even in the presence of extreme weather conditions or hazardous chemicals. Gaskets can also be specialized according to their application. For example, exhaust gaskets are only used for exhaust management purposes, and head gaskets are almost exclusively used to seal engine blocks and cylinder heads in combustion engines.
Across industry, gaskets of all shapes, sizes and compositions are used for sealing applications. The aerospace, automotive, aviation, electronics, military, transportation and countless other industrial operations make extensive use of gaskets. Airframes, appliances, business machines, compressors, elevators, escalators, medical equipment, meters, turbines, pumps, valves, engines, plumbing systems and a host of other varieties of equipment require the use of gaskets in order to function safely and effectively. Seals between joints are critical in many hydraulic, pneumatic and aerospace applications responsible for maintaining air or fluid pressure; in commercial aircraft, for example, gaskets throughout the aircraft keep the cabin from depressurizing. Gaskets have historically played a very important role in the safe operation of equipment. Gasket failure can have catastrophic consequences, as was the case in the explosion of the Challenger space shuttle in 1986. The failure of an O-ring gasket used in the shuttle's fuel system was attributed to low-temperature exposure, which made it become brittle. Engineers give very careful consideration to all of the factors that contribute to gasket operation; when gaskets fail, their failure can devastating.
Most rubber gaskets are die cut from flat rubber or metal sheets. Die cutting allows gasket manufacturers significant design flexibility, and gaskets are cut in shapes as simple as basic rings or as complex as automotive engine blocks. For applications that require simple gaskets with thick, strong construction, rubber molding is used as an alternative to die cutting. Gasket manufacturers use a wide number of both natural and synthetic rubbers to manufacture gaskets with application-specific tolerances. Common elastomeric materials include silicone, neoprene, nitrile, EPDM and Viton. Plastics commonly used for either gasket material or for jacketing include Teflon, nylon, polyethylene (PE), polyurethane and mylar. Sponge rubber like open or closed cell silicone is also used for applications requiring a more flexible seal. Gaskets may be made out of non-asbestos sheets such as carbon filament, fiberglass, ceramics and Kevlar. Metal gaskets and shims, which are flat metal gaskets similar to washers, are used alone or in combination with rubber gaskets to fill additional gaps that may occur within flanges, which is similar to the way metal jacketed gaskets are used to create extra seal strength and corrosion resistance.
Gaskets range in their design from very simple to very complex. The simplest gasket variety is the O-ring, which, as its name suggests, is merely a thin, O-shaped ring. They are almost always made of natural or synthetic rubber, though some metal and plastic ring gaskets could be described as O-rings. More complex gaskets can be textured to fit more effectively in a connection point; such shaped gaskets can be tapered, grooved, ridged or otherwise shaped to create a seal between two objects. In situations in which the point of a connection may be subject to stress, tension or movement, spiral wound gaskets can maintain a tight seal and provide the flexibility necessary to allow movement without breaking. These seals feature interwoven or combined metal and filler materials to provide a combination of strength, flexibility and effective sealing. Head gaskets are among the most complicated gasket varieties. They are used to create a seal between engine blocks and cylinder heads in combustion engines. They must combine features of strength, heat resistance and chemical resistance as they are exposed to the chemicals and heat involved in fossil-fuel combustion engines. Whatever the gasket configuration, every design is engineered to accommodate the conditions of a specific application, and the importance of anticipating all of those conditions cannot be overstated.
Images Provided by Reliant Rubber Company
- Also referred to as "back-up rings," they
are rings designed to fit behind rubber o-ring seals in order to prevent
extrusion into the gap between the metal pieces.
- A lightweight metal that resists corrosion and is used in aerospace materials, springs and gaskets.
- The internal forces that exert pressure against a gasket, which may cause the unsealing of the gasketed joint.
- Flat steel washers in the center of which a rubber sealing ring is molded to fit over a bolt, providing a seal.
- Cutting shapes out of material using a die. The die is a pre-formed stencil.
- An interruption produced by an electric current, which can be filtered out by some gaskets.
- The total force that creates a seal through compression of the gasket.
- The internal forces working against the flanges holding the gasket in place.
- The unevenness of a seal due to differences in the two adjoining surfaces.
- A specialized gasket material that is used in electrical transformers.
- A rubber used in weather resistant products, adhesives, paints, rocket fuel and gaskets.
- A back-up ring that is used as an anti-extrusion ring for an o-ring. Parbacks are concave-shaped on one side.
- Circular sealing devices. - Strips comprised of multiple layers of metal that are welded together to allow gaskets to be used in extreme heat or pressure. - A type of ring that relieves friction by fitting over an o-ring. - Used as spacers between a gasket and the adjoining material. - A seal, created by a gasket, between two unmoving parts. - Flat, circular rings placed under the head of a bolt to serve as spacers, gaskets or slip devices.