Tri-Clamp PTFE Gasket, 2", 4" and 6"

Solid PTFE tri clamp gasket, FDA compliant, in 2, 4 and 6 inch, from $3.25. Every size is priced on this page. PTFE is the only material in this range that rates excellent against isopropyl, and it is the cheapest way to get full chemical resistance. It also runs to -350 F (-212 C), far colder than any elastomer, which matters more than most people expect. Sizes and price Size Price 2 in $3.25 4 in $6.95 6 in $19.95 Solid PTFE is stocked in 2, 4 and 6 inch only. For 1 inch or 1.5 inch, use the PTFE envelope gasket, which puts the same PTFE against the process with a Viton core behind it, or the Viton gasket if the service is not isopropyl and not below -40 F (-40 C). The numbers Temperature: -350 F to 500 F (-212 C to 260 C) Clamp torque: 50 in-lb, the rigid figure. An elastomeric gasket takes 30. Torque a rigid gasket to elastomeric spec and it leaks Compliance: FDA compliant Excellent on: butane, propane, ethanol, heptane, pentane, hexane and isopropyl Behavior: rigid. It does not spring back, it is subject to creep and cold flow, and it wants a high pressure clamp If the joint gets broken and remade every run, the PTFE envelope gasket is the better choice. The Viton core inside gives it the recovery that solid PTFE does not have. Solvent compatibility, by material Material Butane Propane Ethanol Heptane Pentane Hexane Isopropyl PTFE A A A A A A A Viton (FKM) A A A A A A D Buna-N A A C A E A D Silicone D D B D D D D A excellent, B good with minor effect, C fair and not for continuous use, D severe and not recommended, E no data. From the N.B. Oler Sintered Filter Technical Specifications, Rev. 2026.1. Which material for which job Material Temperature Torque Pick it when Solid PTFE -350 F to 500 F (-212 C to 260 C) 50 in-lb Isopropyl, or cold service. Cheapest route to full chemical resistance PTFE envelope, Viton core -100 F to 400 F (-73 C to 204 C) 50 in-lb PTFE chemistry with spring-back, for joints broken every run Viton (FKM) -40 F to 400 F (-40 C to 204 C) 30 in-lb The hydrocarbon default. Not for isopropyl Buna-N -30 F to 250 F (-34 C to 121 C) 30 in-lb Water, food, general sanitary. Cheapest Silicone -85 F to 450 F (-65 C to 232 C) 30 in-lb Steam and food. Severe on every hydrocarbon The cold end, and what actually limits it Minimum solvent temperature on an N.B. Oler system is -40 F (-40 C) on standard elastomeric gaskets, and -65 F (-54 C) with PTFE. Both figures come from 3P Certz and were confirmed in September 2026. On the cold end of a run the gasket is the limiting component, not the vessel, so check the gasket against your lowest process temperature rather than against the vessel rating. What we recommend First choice for most buyers: the PTFE envelope gasket with a Viton filler, also sold as PTFE encapsulated Viton. PTFE chemistry against the process, including isopropyl, with a Viton core that springs back so the joint reseals instead of taking a set. It is the best overall gasket on this site. Default on a hydrocarbon system: Viton, rated -40 F to 400 F (-40 C to 204 C). Note that -40 F and -40 C are the same temperature, which is why both units read -40. Viton is what we run in our own shop, and in our own operating experience it gives the best results in cold service of the elastomers we have used. That is shop experience rather than a laboratory result, and the published rating is still -40 F (-40 C). Replacement and quantities Replace every 3 to 6 months regardless of how it looks Replace immediately on any cracking, tearing, splitting or permanent deformation A gasket that has taken a compression set passes a cold leak check and then weeps once the line comes up to pressure. That is why interval beats inspection on a gasket A 20 LB system takes 22 six inch gaskets. A 40 LB takes 44 Full comparison: Choosing the right gasket material for tri-clamp connections Stocked in Bend, Oregon.