Blog post
Gasket material by temperature and media
The temperature at the flange and the fluid it holds decide the sheet family before anything else. Elastomer sheets split by media at moderate temperatures; fiber, PTFE, graphite and mica sheets take over where the flange runs hotter or the media attacks rubber. This post lists the published band for each sheet family, what it suits, what it does not, and the callout a print uses.
Published , updated
Elastomer sheet by temperature and media (ASTM D2000 callouts)
| Sheet family | Continuous band | Suits | Does not suit | Print callout |
|---|---|---|---|---|
| Nitrile (NBR) | -34 C to 100 C (-29 F to 212 F) | Petroleum oils, fuels, hydraulic fluids, water | Ozone, sunlight and weather, ketones, brake fluid | ASTM D1418 NBR; ASTM D2000 line callouts |
| EPDM | -57 C to 150 C (-70 F to 302 F) | Water, steam, glycol coolants, brake fluid, dilute acids and alkalis, outdoor exposure | Petroleum oils and fuels | ASTM D1418 EPDM; ASTM D2000 line callouts |
| Neoprene (CR) | About -40 C to 121 C (-40 F to 250 F) | Refrigerants, weather, moderate oils | Aromatic and chlorinated solvents, ketones | ASTM D1418 CR; ASTM D2000 line callouts |
| Silicone (VMQ) | -54 C to 204 C (-65 F to 400 F) | Dry heat, cold, ozone, food contact on listed compounds | Fuels, oils, steam, abrasive or moving service | ASTM D1418 VMQ; ASTM D2000 line callouts; A-A-59588 |
| Fluoroelastomer (FKM, Viton®) | -26 C to 204 C (-15 F to 400 F) | Oils, fuels, aromatics, chlorinated solvents, acids | Hot water and steam, ketones, amines, brake fluid | ASTM D1418 FKM; ASTM D2000 line callouts |
| Red rubber (SBR) | The sheet maker's data sheet governs | Water, air, low-pressure general service | Oil, fuel, solvents | MIL-PRF-1149 |
| Butyl (IIR) | -59 C to 121 C (-74 F to 250 F) | Gas permeation resistance, water, weather | Oils, fuels | ASTM D1418 IIR; ASTM D2000 line callouts |
| CSM (chlorosulfonated polyethylene) | The sheet maker's data sheet governs | Ozone, weather, acids, oxidizing chemicals | Aromatic solvents, ketones | ASTM D1418 CSM; ASTM D2000 line callouts |
The elastomer rows are the same families as O-ring compounds. The nitrile, EPDM, neoprene, silicone, fluoroelastomer and butyl bands are the Parker O-Ring Handbook (ORD 5700) figures the temperature guide uses; red rubber and CSM have no handbook band, so the sheet maker's data sheet governs both. Two rules cover most mistakes: nitrile is the oil sheet and fails in weather, and EPDM is the water and steam sheet and fails in oil. The EPDM vs FKM comparison works through the fluoroelastomer side of that split.
Fiber, PTFE, graphite and mica sheet above the elastomer band (ASTM F104)
| Sheet family | Band on the datasheet | Suits | Note | Print callout |
|---|---|---|---|---|
| Compressed non-asbestos fiber (CNAF) | -73 C to 205 C continuous (-100 F to 400 F) | Steam, oils, water, bolted flanges at pressure | Aramid fiber with a nitrile binder | ASTM F104 F71 line callout |
| Expanded PTFE sheet | Set by the grade sheet; see the expanded PTFE page | Strong acids and alkalis, solvents, oxidizers | Conforms to rough or warped flanges at low bolt load | ASTM F104 fluoropolymer type |
| Filled PTFE sheet | Set by the grade sheet; see the PTFE page | The same chemistry as expanded sheet, on steel flanges, valves and pumps | The filler is named on the grade sheet | ASTM F104 fluoropolymer type |
| Flexible graphite | To 450 C (842 F) in air, homogeneous sheet | Steam, hot oils, hydrocarbons at high temperature | Not for strong oxidizers; tanged sheet carries a stainless insert and is cut by the sheet maker | ASTM F104 flexible graphite |
| Mica | To 950 C (1742 F) unreinforced; to 900 C (1652 F) with a perforated stainless insert | Exhaust, furnace and burner flanges | Low pressure only | Maker grade callout |
| Cork-rubber | -30 C to 110 C (-22 F to 230 F) in fluids at 3 mm and thicker; -20 C (-4 F) low below 3 mm | Oil pans, covers, low-pressure fuel and oil | Not for pressure | ASTM F104; SAE AMS-C-6183 |
Sponge and foam sheets (closed-cell sponge, silicone sponge, polyurethane foam) belong to a third group: enclosure and cover seals under light bolt load, chosen by firmness and compression rather than by pressure. Each sheet has its own page under waterjet-cut gaskets, with the maker's figures and the thicknesses offered.
The five questions the print answers
- Temperature: the continuous figure at the flange and the peak, on both sides of the joint. A sheet is chosen on the continuous band; the peak decides whether the next family up is needed.
- Media: every fluid the gasket sees, including cleaning agents, coolant additives and the vapor above a liquid. One incompatible fluid rules a family out on its own.
- Pressure and bolt load: rubber sheets seal at low pressure and light load. Fiber, PTFE and graphite sheets take a hard-bolted flange and carry a pressure rating on the datasheet.
- Thickness and compressibility: thin sheet for machined flanges, thicker sheet to take up warp and surface damage. Compressibility and recovery are the ASTM F36 figures on the datasheet.
- Adhesive backing and finish: a pressure-sensitive adhesive holds a gasket in place during assembly, and its own temperature limit becomes part of the specification.
Reading the callout
Three families of callout appear on gasket prints. ASTM F104 classifies non-metallic gasket sheet by type and class (fiber, cork, fluoropolymer, graphite and so on), and a line callout adds the tested properties. ASTM D2000 classifies rubber by a type letter for heat resistance and a class letter for oil swell, so BF, CA and HK are bands, not products. MIL-PRF-1149 and the SAE AMS documents name a sheet by grade and are used on military and aerospace prints.
The print governs. A sheet from another family that appears to cover the same band is a change the buyer approves on the drawing, not a substitution made at the quote. The chemical compatibility guide lists the media questions to settle before that change is proposed.
From sheet to gasket
Conquest cuts gaskets from any of these sheet families on a waterjet, to your drawing, and the sheet's material certification travels with the lot. The pages for EPDM, FKM, CNAF, expanded PTFE and flexible graphite carry the full datasheet figures behind the rows above. When a gasket has already failed in service, the failure modes post reads the same surface signs on a flat seal.
Viton is a trademark of The Chemours Company; Garlock® and BLUE-GARD® are trademarks of Garlock Sealing Technologies; GRAFOIL® is a trademark of NeoGraf Solutions; Parker is a trademark of Parker Hannifin Corporation; KLINGER®, Milam® and Nebar® are trademarks of their owners. No affiliation or endorsement is implied.
Sources
- Garlock BLUE-GARD 3000 spec sheet (January 2016); NeoGraf Solutions, GRAFOIL flexible graphite product page; KLINGER Thermoseal, KLINGER Milam PSS product page; James Walker, Nebar cork-elastomer jointing datasheet; American Biltrite, MIL-PRF-1149 type I class 2 SBR sheet product page; read 2026-09-27
- EagleBurgmann, Statotherm HT 9560 mica gasket sheet product page (unreinforced 9560, continuous operation to 950 C), read 2026-10-13
- Parker O-Ring Handbook ORD 5700, section 2.2, the elastomer temperature bands, read 2026-09-14
- ASTM F104, Standard Classification System for Nonmetallic Gasket Materials; ASTM D2000, Standard Classification System for Rubber Products in Automotive Applications; MIL-PRF-1149 (titles only)
Frequently asked questions
Which gasket material handles the highest temperature?
Mica, then flexible graphite, on the datasheet bands above. Compressed non-asbestos fiber covers most bolted flanges to 205 C continuous; the elastomer sheets stop around 200 C and most of them well below it.
Which sheet for steam?
EPDM at low pressure and moderate temperature, compressed fiber or flexible graphite on a bolted flange at pressure. Standard fluoroelastomer and nitrile sheet are not steam materials.
Can nitrile sheet be used outdoors?
No. Nitrile cracks in ozone and sunlight. EPDM, neoprene and CSM are the weather sheets; the fluid inside the joint decides among them.
Is EPDM safe with oil?
No. EPDM swells in petroleum oils and fuels. Nitrile covers oil at moderate temperature and fluoroelastomer covers it hot.
Does thickness change the material choice?
Not the family, but a thicker sheet of the same family seals a rougher flange and carries a lower pressure rating on most datasheets. Match the thickness to the flange finish and the callout.
What does an ASTM F104 callout tell me?
The type and class of sheet, and the tested properties the maker certifies: compressibility, recovery, tensile strength, fluid immersion behavior and thickness. It is the way a print names a non-metallic gasket sheet without naming a brand.
Related guides
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