Ethylene Propylene

Ethylene Propylene-Diene Terpolymer (EPDM) or Ethylene-Propylene Copolymer (EPM)

• Resistant to animal and vegetable oils, strong and oxidizing chemicals and ozone
• Attacked by petroleum oils and solvents, and aromatic hydrocarbons (I.E. toluene, benzene, xylene, etc.)
• Excellent weathering properties, low temperature resistance, low permeability to air, and good dielectric strength
• Good bonding properties (Expansion Joints)
• Temperature limit: 300°F (149°C)

Fluoroelastomer

Hexafluoropropylene-Vinylidene Fluoride (FKM or FPM)

• Most common trade names: DuPont VITON® and 3M FLUOREL®
• Resistant to aliphatic, aromatic, and halogenated hydrocarbons, acids, animal and vegetable oils
• Attacked by ketones, low molecular weight esters, and nitro-containing compounds
• Good weathering properties and resistance to elevated temperatures
• Available in several types and grades
• Temperature limit: 400°F (205°C)

Neoprene

Chloroprene (CR)

• Resistant to moderate chemicals, acids, oils, fats, grease, many solvents, and ozone
• Attacked by strong oxidizing acids; esters; ketones; chlorinated, aromatic, and nitro hydrocarbons
• Good weathering resistance
• Flame retarding

Natural Rubber

Isoprene

• Generally resistant to most moderate wet or dry chemicals, organic acids, and alcohols
• Attacked by strong acids, fats, oils, grease, most hydrocarbons, and ozone
• Excellent physical properties including abrasion and tear resistance
• Temperature limit: 180°F (82°C)

Nitrile or Buna-N

Acrylonitrile Butadiene (NBR)

• Generally resistant to fats, oils, greases, and aliphatic hydrocarbons
• Not ozone resistant
• Attacked by ketones; esters; aldehydes; and aromatic, chlorinated, and nitro hydrocarbons

SBR or Buna-S

Styrene Butadiene (SBR)

• Fluid compatibility is similar to “Natural”
• Good physical properties

Aramid

• Man-made organic fiber
• Introduced by DuPont under the trade name KEVLAR® in the early 1970s
• Good wear resistance
• Good thermal and electrical insulation properties
• Very high tensile strength, high modulus, and low density
• Starts degrading between 500°F (260°C) and 600 °F (315°C) with very little aramid left at 800°F (425°C)
• Attacked by concentrated hot acids or caustics

Carbon

• Rod-like fibers of various diameters and lengths
• Produced by pyrolysis (heat treatment process) to various levels of carbon content materials (I.E. rayon, acrylonitriles, pitch, etc.)
• Good heat and chemical resistance

Cellulose

• Natural fibers; most common: cotton and so-called “vegetable” fibers
• Readily available in huge quantities; low price
• Moderate chemical and general fluid resistance
• Not generally recommended for use over 250°F (121°C)

Fiberglass

• Excellent heat resistance and incombustible
• Begins to degrade at approximately 750°F (399°C)
• Does not absorb moisture; will not rot or decay
• Resistant to acids, oils, many solvents, weather, and corrosive vapors
• Electrical insulator
• Used in combination with aramid fiber to reinforce Garlock expansion joints

Graphite

• Rod-like fibers of various diameters and lengths
• Produced by special heat treatment of carbon fibers at approximately 5072°F (2800°C)
• Excellent heat and chemical resistance
• Versatile; popularity in the gasketing industry continues to grow

Mineral/Rock

• Fibers are amorphous and highly homogenous because of their metamorphosis from volcanic rock
• Do not burn; chemically inert
• Resistant to high temperatures; above 930°F (500°C)

NYLON®

Tire Cord (expansion joints)

• Man-made polyamide with high tensile strength and good ultimate elongation properties
• Good resistance to common solvents, fuels, oils, and greases
• Attacked by strong alkalines (caustics) and acids, oxidizing agents, phenol, and formic acid
• Temperature limit: 250°F (121°C)

Polyester

• High quality, synthetic material
• In spun form, polyester has a very high density and thread count, making it resistant to permeation
• Polyester cloth is considered the standard reinforcement material in Garlock expansion joints

Graphite

• One of the two crystalline forms of the element carbon (The other is diamond); man-made carbon, graphite, and diamonds also exist
• One of the most stable and chemically-resistant materials in the world
• Does not melt, but sublimes; changes from the solid to gas state, bypassing the liquid state, at temperatures over 5400°F (2980°C), or, in the presence of oxygen oxidation, above 850°F (450°C)
• Excellent conductor of heat and electricity
• Readily available in various forms; moderately priced to very expensive

Polytetrafluoroethylene (PTFE)

• Man-made thermoplastic introduced in the late 1940s or early 1950s
• Extremely good chemical inertness and resistance to a wide range of fluids; only a few, very rare fluids will attack it
• Withstands a wide temperature range, from -450°F (-268°C) to 500°F (260°C)
• A very low static coefficient of friction; very slippery
• Poor heat conductor; good heat insulator
• High coefficient of thermal expansion; swells significantly under heat
• Flows (creeps) under relatively low loads, even at room temperature (usually stated as “cold flow”)
• Can be readily blended with other materials to improve its features and performance characteristics
• Readily available at moderately high prices

FEP

Fluorinated Ethylene Propylene

• Similar chemical resistance to that of PTFE
• In terms of Garlock® products, predominately used as the liner material in GUARDIAN® Expansion Joints
• Temperature limit: 450°F (232°C)

Aluminum

• Excellent corrosion resistance to fresh and salt water
• Maximum recommended operating temperature is 800°F (472°C)

Brass

• Copper alloy typically used with non-oxidizing acids, alkaline, and neutral salt solutions
• Maximum recommended operating temperature is 500°F (260°C)

Carbon Steel

• Most common metal for double-jacketed gaskets
• Poor resistance to corrosion
• Not recommended for water or diluted acids
• Maximum recommended operating temperature of 1000°F (540°C)

Copper

• Used successfully in acetic acids, nitrates, and many organic chemicals
• Maximum recommended operating temperature of 600°F (316°C)

HASTELLOY B®

• Registered Trademark of Haynes International
• Corrosion-resistant alloy
• Resists hydrochloric acid, phosphoric acid, other halogen acids, and reducing conditions
• Maximum recommended operating temperature of 2000°F (1090°C)

HASTELLOY C®

• Registered trademark of Haynes International
• Alloy with exceptional resistance to severe oxidizing conditions in nitric acid, free chlorine, and strong aqueous and acid solutions
• Maximum recommended operating temperature is 2000°F (1090°C)

INCONEL®

• Registered trademark of Inco Alloys International, Inc.
• Excellent resistance to corrosion by halogen gases and compounds
• Withstands high temperatures; maximum operating temperature of 2000°F (1090°C)

MONEL®

• Registered trademark of Inco Alloys International, Inc.
• Excellent resistance to most acids and alkalines, except extremely oxidant acids
• Commonly used in hydrofluoric acid applications
• Maximum recommended operating temperature of 1500°F (820°C)

Nickel

• Resists caustic media and corrosion from neutral and distilled water
• Maximum recommended operating temperature of 1400°F (760°C)

Stainless Steel Type 304

• Widely used for industrial gasketing
• Excellent corrosion resistance
• Maximum recommended operating temperature of 1400°F (760°C)

Stainless Steel Type 316L

• Greater corrosion resistance than SS Type 304, due to added molybendum
• Maximum recommended operating temperature of 1400°F (760°C)

Stainless Steel Type 321

• Similar to SS Type 304, but has titanium added
• Widely used in high-temperature corrosive applications
• Maximum recommended operating temperature of 1400°F (760°C)

Stainless Steel Type 347

• Similar to SS Type 304, but has columbium and titanium added
• Good performance in high-temperature corrosive applications, to 1600°F (870°C)

Stainless Steel Type 410

• Martensitic stainless steel
• Heat-treatable, 12% chromium steel
• Good corrosion resistance, high strength
• Maximum recommended operating temperature of 1200°F (650°C)

Titanium

• Good resistance to wet chlorine and chlorine dioxide
• Not suitable for dry chlorine
• Maximum recommended operating temperature of 2000°F (1090°C)

Barium Sulfate

• Commonly called “Barytes”
• Natural and mined from the Earth, or can be synthetically manufactured
• Good resistance against almost all fluids, except for concentrated sulfuric acid
• Used in rubber products, compressed gasketing, and GYLON® Style 3510

Carbon Black

• Same characteristics as carbon/graphite
• Not recommended for temperatures over 850°F (450°C) in oxidizing atmosphere, or for strong chemical oxidizers
• Used in some rubber products and compressed gasketing to enhance properties, such as chemical resistance

Ceramic

• Fibrous, aluminosilicate filler material
• Generally used for high-temperature, low-pressure applications, where sealability is not a primary concern
• Does not interlock and densify under compressive stress, unlike other non-asbestos materials
• Used in spiral wound gaskets
• Valued for high-temperature capability to 2000°F (1090°C)

Flexible Graphite

• Used in tape form as a filler in spiral wound gaskets
• Excellent chemical resistance and fire safety
• Temperature capability to 950°F (510°C) depending on grade of flexible graphite and application
• Material makeup, such as leachable halogen content, can be controlled
• Ideal for nuclear applications

PTFE

• Widely used in GYLON® and spiral wound gaskets
• High chemical resistance, low permeability
• Especially successful in hydrocarbon alkylation units in refineries and in food-related industries
• Temperature limitation with this material; not fire-safe

Silica

• Natural material (sand)
• Many different structures, all with similar properties
• Recommended for most all fluids except inorganic fluorides, like hydrofluoric acid, and strong caustics