PTFE is the closest thing gasketing has to a universal chemical answer: inert to almost everything on the reactivity chart, FDA-compliant, and clean enough for pharmaceutical and semiconductor service. Its one weakness — cold flow under bolt load — is why there are three distinct families of PTFE gasket, and why choosing between them matters.

Virgin PTFE

Skived or molded virgin PTFE sheet offers maximum chemical purity, which matters in ultra-pure water, pharma WFI loops, and semiconductor chemical delivery. The trade-off is creep: under sustained bolt stress it slowly flows, bolts lose preload, and joints loosen. Keep virgin PTFE to low pressure classes and consider live-loading (Belleville washers) on critical joints.

Filled PTFE

Adding glass, barium sulfate, or silica dramatically reduces creep while preserving most of the chemical resistance. Filled PTFE is the standard for steel piping flanges in acid and caustic service up to 500°F. Match the filler to the media — glass-filled grades aren't suitable for hydrofluoric acid or hot caustics, where a barium-sulfate-filled grade holds up.

Expanded PTFE (ePTFE)

Expanded PTFE is soft, highly conformable, and seals warped, pitted, or glass-lined flanges at low bolt loads where nothing else will. Joint sealant tape versions let you form a gasket in place on large or odd-shaped flanges. For fragile equipment — glass-lined reactors, FRP, plastic-faced flanges — ePTFE is usually the first call.

Selection at a Glance

Handling & Torque Notes

PTFE gaskets need accurate torque more than most: under-torque and they leak, over-torque and they extrude. Follow the manufacturer's gasket stress targets, retorque per procedure (not hot), and never reuse a PTFE gasket after breakout.

Cut to Your Spec

We supply virgin, filled, and expanded PTFE gaskets in standard ANSI sizes and custom-cut shapes, with material certifications available. Put your size, class, media, and temperature in the quote form above — pricing and lead time back within 1–2 business hours.