When two pieces of equipment are bolted together they seldom have perfectly flat faces. The small imperfections create small escape routes where liquids, gases, or dust get lost or find their way, and contamination makes its way in. Gaskets are an excellent solution to this leaking problem. Gaskets are compressible sealing elements that are installed between two surfaces, then compressed to fill any microscopic gaps. Gaskets seal in either fluid or air, dampen vibration, provide cushioning between components, and contribute to cleanliness where food contacts equipment. They make imperfect joints into leak-tight assemblies.

This guide will describe what is a gasket, describe common types and materials of gaskets, describe where industrial gaskets are found, and provide helpful guidance on how to select the right gasket seal for your application. Whether you need rubber gaskets for an HVAC system, or metal gaskets on a high-pressure oil pipeline, you will make a better choice having knowledge of the available options.

What is Gasket?

A gasket is a flexible mechanical seal between two static surfaces to restrict flow through a channel of compressed material, filling irregularities that may cause leaking. Amongst the simplest is a flat solid or foam rubber ring, while the most complicated could be engineered multilayer techniques for use in high level stress or loads. Unlike a dynamic seal which is to form a barrier for fluids or gases in a moving shaft, gaskets connect two static parts forming a pressure-tight barrier. The gasket provides restrictions to leakage, restricts wear while maintaining contact stress with thermal cycling and vibration, and protects assemblies against damage by expanding the contact surface and avoiding metal contact. Regardless of the applications, gasket failure can equate to contamination, downtime or safety incidents. Gasket materials are almost endless however when a gasket is recommended it is suggested that materials are chosen with intent. State of the art elastomers are found as NBR (nitrile), EPDM (ethylene propylene), and silicone; PTFE (teflon) or graphite sheets; semi-metallic or metallic gaskets are commonly spiral wound or ring-type joints mixing rubber and metal. Gasket selection should be based on the process media, operating temperature and pressure, available bolt load, joint movement/thermal cycling, and the flange face type and surface finish.

Types of Gaskets

Gaskets are classified by construction and by the materials used. Below is an overview of the main gasket types and their typical uses.

Category	Typical styles	Key features & common applications
Non‑metallic gaskets	Rubber gaskets, PTFE gaskets, cork gaskets, elastomeric gaskets	These gaskets are cut from compressible sheet materials such as nitrile rubber, silicone, EPDM, PTFE or cork. They offer good flexibility and are suited to low‑ and moderate‑pressure duties like water pipes, HVAC systems, pumps, food‑processing equipment and pharmaceutical vessels. Rubber gaskets are widely used in automotive door and trunk seals and industrial machinery Cork gaskets resist oil and fuel and appear in engines and fuel pumps
Semi‑metallic gaskets	Spiral wound gaskets, Kammprofile gaskets, metal‑jacketed gaskets	Semi‑metallic gaskets combine metal for strength with filler materials for compliance. Spiral wound gaskets are made by winding a metal strip (often stainless steel) and a soft filler (graphite or PTFE) into a spiral. They exhibit excellent elasticity and can handle high pressures and temperatures, making them common in pipelines, heat exchangers and boilers. Kammprofile gaskets have a serrated metal core with a soft facing; they compress and recover well and suit flanged joints subject to temperature and pressure cycling. Metal‑jacketed gaskets consist of a non‑metallic core (often graphite) wrapped in a thin metal sheet (stainless steel or copper); they are used in medium‑ to high‑pressure pipelines and corrosive media
Metallic gaskets	Ring joint gaskets, serrated/corrugated metal gaskets	Metallic gaskets are machined from metal and used in extreme conditions. Ring joint gaskets (RTJ) are solid metal rings with oval or octagonal cross‑sections that fit into machined grooves in flanges; they provide leak‑tight seals in high‑pressure, high‑temperature systems such as API 6A valves and wellheads. Serrated metal gaskets have concentric grooves; they resist high pressure but require heavy bolt loads to compress. Corrugated metal gaskets use thin corrugated metal to enhance elasticity and are suited to heat exchanger flanges.

Common Gasket Materials and Their Applications

Rubber (Elastomeric) Gaskets

Synthetic rubber gaskets have been used since Charles Goodyear’s vulcanized rubber in the mid‑1800s. They can be made from natural or synthetic elastomers and are among the most versatile gasket materials. Rubber gaskets are ubiquitous in automotive applications, sealing doors, trunk lids and engine components because they exclude moisture and contaminants. Rubber gaskets also seal pumps, valves and conveyors exposed to heat and chemicals.

Common elastomers and typical temperature ranges

Elastomer	Typical applications	Approx. temperature range*
Nitrile (NBR)	Fuel systems, hydraulic equipment, general‑purpose oil seals	−60 °F to 225 °F
Ethylene‑propylene (EPDM)	Hot water and steam, automotive cooling systems, outdoor seals	−70 °F to 250 °F
Silicone (VMQ)	Food processing, medical devices, high‑temperature static seals	−75 °F to 450 °F
Neoprene	HVAC systems, refrigeration seals, moderate‑temperature industrial seals	(Typically −50 °F to ~225 °F; wide flexibility and chemical resistance)
Fluorocarbon (Viton / FKM)	Chemical processing, aerospace, high‑temperature oil service	−15 °F to 400 °F

*Temperature ranges are approximate and depend on formulation; always verify compatibility for your specific application.

PTFE (Teflon) Gaskets

PTFE is a fluoropolymer noted for its exceptional chemical resistance, low friction, and dielectric strength. PTFE gaskets are inert and non‑porous, so they do not support bacterial growth, making them ideal for food processing, pharmaceutical manufacturing and semiconductor fabrication. They also perform well in aggressive chemical environments (acids, solvents) and can handle temperatures from roughly 10 °F to 400 °F. Pure PTFE tends to cold‑flow under load; fillers such as glass fibre or graphite are used to improve creep resistance and increase pressure capability

Spiral Wound Gaskets

Spiral wound gaskets are an assembly of alternating layers of metal strip and filler material wound in a spiral orientation. The metals are commonly stainless steels (304/316) for corrosion-resistance, while fillers can be various materials such as graphite or PTFE that will conform and seal. The composite nature of spiral wound gaskets allows for great elasticity and can accommodate the movement of flanges, as well as giving the ability to withstand much higher pressures and temperatures up to approximately 800 °C. Spiral wound gaskets are used frequently in petrochemical pipelines, boilers, heat exchangers and refineries.

Metal Jacketed Gaskets

Metal jacketed gaskets are semi‑metallic seals consisting of a soft non‑metallic core (such as graphite) wrapped in a thin metal shell (often stainless steel or copper). The metal jacket provides structural strength and protects the filler from thermal shock, while the core ensures compliance. They are suitable for medium‑ to high‑pressure pipelines and corrosive process media such as heat exchangers and reactors.

Ring Joint Gaskets (RTJ)

Ring joint gaskets are precision‑machined solid metal rings with oval or octagonal cross‑sections designed to fit into a matching groove in a flange. Under bolt load, the ring plastically deforms, creating a metal‑to‑metal seal. These gaskets are used for high‑pressure, high‑temperature systems such as oil and gas wellheads, API 6A valves and high‑pressure pipelines. Because of the high stresses involved, RTJs require flanges with precisely machined grooves and sufficient bolt loading.

How to Choose the Right Gasket

Selecting the correct gasket is vital for safety, reliability and cost‑effectiveness. Consider the following factors:

Pressure, temperature and media: Establish the operating pressure and temperature envelope. If the system operates at high pressures or temperatures, it may require semi‑metallic or metallic gaskets (e.g. spiral wound, RTJ); however, if the system operates at low pressure water or air, a rubber or PTFE gasket may be sufficient. Determine the nature of the fluid or gas it will be sealing; chemically aggressive media will need compatible materials (PTFE or Viton).
Mechanical design and flange type: Soft gaskets are generally used in flat‑face flanges, spiral wound gaskets are used in raised face flanges, and ring joint gaskets are used with RTJ flanges. Be sure that the flange and bolt design can produce the compressive load necessary for the gasket you are using.
Static vs. dynamic application: You can generally use most gasket types for static joints, including pipe flanges; dynamic seals (e.g. rotating shafts) require seals instead of gaskets – do not confuse gaskets with seals; seals will always have to allow for relative motion on the moving parts.
Regulatory and hygiene requirements: Food, beverage and pharmaceutical applications may have FDA compliant materials (e.g. silicone, PTFE).
Cost and maintenance: Non‑metallic gaskets are generally inexpensive but may need to be changed often; metallic gaskets may not be as cheap but will often last longer. If there is equipment that you frequently disassemble, be sure to select its gaskets to be easily removed and replace (e.g., spiral wound gaskets).

Applications of Gaskets

Gaskets are static sealing elements used to prevent leaks, maintain pressure, and protect product purity at equipment interfaces. Some of the areas where gaskets are used include:

Household & consumer: Refrigerator doors, window/door seals, appliance housings, HVAC plenums for air and moisture control.
Automotive & transportation: Engine, exhaust, fuel and cooling system joints that face oils, fuels, coolants and thermal cycling.
Building services & plumbing: Potable water, steam and drain lines at pump/valve flanges and meter unions in low to moderate pressure.
Food & beverage: Hygienic pipelines, fillers, sight glasses and manways that must withstand CIP/SIP chemicals and hot water/steam.
Pharmaceutical & biotech: Reactors, filtration skids, WFI and clean-steam lines where sterilization and zero-contamination are critical.
Chemical processing: Reactors, columns, heat exchangers, pumps and valves handling corrosive media and temperature swings.
Oil & gas (up/mid/downstream): Wellheads, manifolds, high-pressure lines and process equipment requiring groove-type or high-integrity seals.
Power generation & utilities: Boilers/HRSGs, steam lines, condensers and cooling water circuits exposed to high temperature and cycling.
Water & wastewater: Treatment plants, pump stations and chemical dosing lines in continuous aqueous service.
Mining & minerals: Slurry pipelines, thickeners and tailings systems with abrasion, vibration and chemical exposure.
Marine & shipbuilding: Seawater cooling, ballast and fuel systems where corrosion resistance and vibration tolerance are needed.
Aerospace & defense: Airframe, engine, fuel and hydraulic interfaces across wide temperature and pressure envelopes.
Electronics & EVs: Battery pack lids, device enclosures and EMI/RFI shielding where sealing and conductivity often combine.
HVAC (commercial/industrial): Duct flanges, AHUs, chillers and pump/valve interfaces for airtight, watertight joints.
Pulp & paper: Digesters, bleach plants and steam/condensate networks with hot alkaline/acid media.
General manufacturing: Gearboxes, compressors, mixers and machinery flanges that need reliable static sealing in oils, solvents and cleaners.

Maintenance Tips for Gaskets

Regular inspection. Periodically check gaskets for signs of wear, cracking, hardening, extrusion or chemical attack. Replace any gasket showing damage.
Proper installation. Follow the manufacturer’s recommended bolt torque and tightening sequence. Uneven compression can lead to gasket failure. Use calibrated torque wrenches and retorque after initial operation if required.
Surface preparation. Ensure mating surfaces are clean, free of debris and within flatness tolerances. Even the best gasket cannot compensate for severely damaged flanges.
Appropriate storage. Store gaskets in a cool, dry location away from sunlight and ozone to prevent premature aging.
Know when to replace. Gaskets are consumable items. Replace them whenever equipment is disassembled or when operating conditions change (temperature/pressure increases or a more aggressive fluid is introduced).

The Bottom Line

Gaskets may appear to be an uncomplicated object, they are crucial to the safety and efficiency of innumerable mechanical systems. Knowing what gaskets are, the types of gaskets, and properties of gasket materials will assist engineers and maintenance groups build and maintain leak-free systems. The time taken to appropriately consider a gasket based on pressurization, temperature, media, and mechanical aspects is an investment toward avoiding costly downtimes and potentially hazardous maintenance concerns. If there are ever any doubts concerning a gasket selection, consider consulting a knowledgeable gasket supplier or engineer who can help collect relevant information about the application and provide you with the best gasket seal recommendation. Correctly selecting a gasket means weighing multiple variables such as pressure, temperature, media compatibility, regulatory regulations and costs. If you need assistance in selecting or designing gaskets for a project, Jade Special Metals can help provide you both gaskets and assistance, along with quality aftermarket gaskets for use in Applications. Please don’t hesitate to reach out if you have sealing challenges and would like to discover the optimum gasket solution for your application.