Gaskets

About Gaskets and Gasket Manufacturers Including: EPDM Gaskets, Exhaust Gaskets, Gasket Materials, Head Gaskets, High Temperature Gaskets, Jacketed Gaskets, Neoprene Gaskets, Rubber Gaskets, Silicone Gaskets, Spiral Wound Gaskets, Teflon Gaskets & Viton Gaskets.

Gaskets are used to create a tight seal between two parts which prevents gases or fluids from leaking. A proper seal will prevent leakage during temperature or pressure changes. Some gaskets are made to withstand electromagnetic and radio frequency interference (EMI and RFI); these are EMI gaskets, which are made from special EMI-blocking materials (such as nickel). Gaskets must be more pliable than the two adjoining surfaces in order for gaskets to work properly; this allows them to mold to the groves of both components, creating a seal. For this reason, most gaskets materials are either synthetic or natural rubbers; rubber gaskets may include viton gaskets, EPDM gaskets, neoprene gaskets, silicone gaskets and a number of other rubber materials. Additionally, gaskets must be chemically compatible with the two joining surfaces. This ensures a tight seal with no fluid or gas leaks. While most gaskets used in low to mid demand applications are die cut rubber, spiral wound gaskets, metal jacketed gaskets and coated teflon gaskets are used as high temperature gaskets or chemically resistant gaskets in high demand applications. Additionally, gaskets can be designed for specific applications, such as exhaust gaskets in the automotive industry.

Gaskets of various materials, sizes and configurations are used for sealing applications across the aerospace, automotive, aviation, electronics, military and transportation industries. Some applications include air frames, appliances, business machines, compressors, elevators, escalators, medical equipment, meters, turbines and valves. Seals between joints are critical in many hydraulic, pneumatic and aerospace applications responsible for maintaining air or fluid pressure; in a commercial flight, gaskets throughout the aircraft keep the cabin from depressurizing. For especially high demand applications, particularly where high levels of pressure are applied to the seal, metal jacketed gaskets optimize temperature and chemical performance. These gaskets combine the temperature resistance of a metal jacket with the sealing performance of a soft filler. Single jacket gaskets are the most basic type, while double jackets gaskets are available for extra rigid applications, and french style jacket gaskets with two- or three-piece construction have irregular shapes.

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 head gaskets automotive engine blocks. For applications which require simple gaskets with thick, structurally sound 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, such as 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, ceramic 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, similarly to the way metal jacketed gaskets are used to create extra seal strength and corrosion resistance.

Gaskets are molded, die cut and roll formed into configurations to meet every possible sealing application, and there are few ways to substitute the efficiency and function of a gasket seal. O-rings are specific types of circular molded gaskets which are used in simple, primarily static sealing applications; while o-rings can provide an exceptionally strong seal around simple ring flanges, they cannot provide the kind effective seal in non-circular or complex flanges that die cut and molded gaskets are capable of providing. Soft non-polymer materials, are sometimes die cut into gaskets to create a breathable seal; these materials include cork sheet, felt, vegetable fiber, vulcanized hard fiber, chipboard and fishpaper.

Gaskets and Gasket Manufacturers Images Provided by Reliant Rubber Company

Gaskets Types

• Composite gaskets are custom-fit to individual applications and are typically applied with a gasket dressing or adhesive in assembly and sealing. Composite gaskets are made from any combination of the following materials: cork, rubber, paper and felt.
  
• Corrugated gaskets are metal gaskets that may be surface-treated with ceramic, non-asbestos or flexible graphite. Corrugated gaskets, which may be used with Teflon envelopes, provide a seal at low seating stress.
  
• Die cut gaskets are made of materials that can be cut before assembly.
  
• ElastaGraph gaskets are corrugated gaskets that are suitable for high temperature, high pressure applications and consist of a metallic core over which a seamless flexible graphite is applied. ElastaGraph gaskets have a high density inner ring to increase sealability and provide low minimum seating stress.
  
• Encapsulated gaskets consist of a gasket of one material and a continuous layer of another material, typically Teflon, which completely encloses the gasket.
  
• Envelope gaskets consist of a gasket of one material and an envelope of another material, typically Teflon, which covers the gasket.
• EPDM gaskets are made of a synthetic rubber that serves as a seal between two mating surfaces in machine parts.
• Exhaust gaskets provide a seal on exhaust parts in vehicles to guarantee that when gases leave the engine, they stay in the exhaust system until they are expelled into the atmosphere.
• Fibre seal rings are diecut, water-jet cut or formed gaskets or rings that provide a seal between two surfaces.
  
• Flange gaskets have protruding rims or lips that aid in the attaching process.
  
• Foam gaskets are made out of strips of plastic, foam or rubber.
• Gasket materials are various materials with sealant qualities that are used in gasketing applications.
• Head gaskets are inserted between the cylinder head and the engine block. Head gaskets prevent coolant from entering the cylinders.
• High temperature gaskets help prevent leakage of fluids and gas by providing an airtight seal between gaps in machine parts whose temperatures may exceed 500° F.
• Hollow tube gaskets have a tubular cross section that is typically made out of rubber or plastic.
  
• Jacketed gaskets combine the durability of a metal jacket with the sealing capability of a soft gasket.
  
• Laminated gaskets consist of two or more layered materials and are often enclosed in an envelope.
• Neoprene gaskets are made of synthetic rubber and create a long-lasting seal for gaps on machine parts in several industries.
• O-rings also referred to as "donut-shaped" gaskets, are circular rings, having a variety of cross-sectional configurations that are specified by their dimensions, material and hardness. O-rings are installed in a gland to close off a passageway, preventing the escape or loss of fluids or gases.
  
• Profiled and serrated gaskets are solid metal gaskets with surface grooves, which facilitate a good seal with low seating stress. To protect flange surfaces, profile and serrated gaskets can be jacketed.
  
• Rubber gaskets are rubber components that create a seal between two parts.
• Silicone gaskets (formed-in-place) are made from an uncured blend of a silicone compound that is applied to the mating parts and allowed to cure after assembly.
  
• Solid metal gaskets are gaskets made out of solid metal, yet they must be softer than the materials of the two adjoining surfaces. Solid metal gaskets are used for extreme pressures or temperatures.
  
• Spiral wound gaskets are made of a thin metallic strip and a soft nonmetallic filler that are wound together. Spiral wound gaskets can withstand high pressure and extreme temperature.
  
• Teflon gaskets are gaskets designed to resist sticking to the adjoining materials.
• Viton gaskets are made of a synthetic tube that is resistant to heat, oil, and various acids.

Gaskets Terms

Anti-Extrusion Rings - 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.
 
Beryllium Copper - A lightweight metal that resists corrosion and is used in aerospace materials, springs and gaskets.
 
Blowout Pressure - The internal forces that exert pressure against a gasket, which may cause the unsealing of the gasketed joint.
 
Bonded Seals - Flat steel washers in the center of which a rubber sealing ring is molded to fit over a bolt, providing a seal.
 
Die Cutting - Cutting shapes out of material using a die. The die is a pre-formed stencil.
 
Electromagnetic Interference - An interruption produced by an electric current, which can be filtered out by some gaskets.
 
Flange Load - The total force that creates a seal through compression of the gasket.
 
Hydrostatic End Force - The internal forces working against the flanges holding the gasket in place.
 
Mismatch - The unevenness of a seal due to differences in the two adjoining surfaces.
 
Nebar - A specialized gasket material that is used in electrical transformers.
 
Neoprene - A rubber used in weather resistant products, adhesives, paints, rocket fuel and gaskets.
 
Parback - A back-up ring that is used as an anti-extrusion ring for an o-ring. Parbacks are concave-shaped on one side.
 
Rings - Circular sealing devices. Seal Strips - Strips comprised of multiple layers of metal that are welded together to allow gaskets to be used in extreme heat or pressure.

Slip O-ring - A type of ring that relieves friction by fitting over an o-ring.

Shims - Used as spacers between a gasket and the adjoining material.

Static Seal - A seal, created by a gasket, between two unmoving parts.

Washers - Flat, circular rings placed under the head of a bolt to serve as spacers, gaskets or slip devices.