Non-Metal Sealing Gaskets - The Future of Safe and Sustainable Sealing Solutions

Non-metal sealing gaskets built to ASME B16.21 are the safe, sustainable answer to the old asbestos sheets: compressed non-asbestos fiber, aramid, PTFE or graphite seals flanged joints without the health hazard. They seat like our flange gaskets across low-to-moderate pressure duties.

Why Asbestos-Free Matters

Asbestos fiber seals well but lodges in lung tissue and causes cancer and asbestosis, so it is banned or restricted in most markets. ASME B16.21 covers non-metallic flat gaskets with no asbestos, setting dimensions, performance and test expectations for NPS 1/2 to 24. Switching is not only a compliance move — it removes a lifelong liability from maintenance crews who cut and fit gaskets every day.

• Aramid (Kevlar) fiber — tensile strength and heat resistance in the sheet.
• Cellulose fiber — good chemical compatibility for mild media.
• PTFE sheet — broad chemical resistance for clean and aggressive service.
• Graphite sheet — high-temperature, creep-resistant sealing.

Composition and Materials

Modern sheets combine fiber with a binder — nitrile for oils, SBR for general service, sometimes EPDM for water and steam. The fiber gives strength; the binder holds the sheet together and lets it flow into the face serrations. PTFE and graphite sheets trade flexibility for chemical or temperature range. None contain asbestos, and all cut easily on site.

Key Benefits

• No respirable fibre hazard for installers and maintenance crews.
• Meets ASME B16.21 dimensional and performance expectations.
• Wide material menu — the sheet matches the media, not the other way round.
• Economical and easy to cut to shape on site.

Where They Are Used

Non-metal sheets seal water, air, HVAC, food processing, mild chemicals and general plant piping. They suit Class 150 and 300 flanged joints where pressure and temperature stay inside the sheet's rating, and the fluid is not a strong solvent.

In the Joint

The sheet sits between the faces and the bolts compress it until it fills the imperfections; the pipe flanges carry the pipe and the bolt load. Match the sheet to the media, torque evenly in a cross pattern, and never reuse a crushed gasket.

Selection and Installation

Pick the sheet by fluid first — nitrile-bound fiber for oils, aramid or graphite for heat, PTFE for aggressive chemicals. Check the flange face style: raised face takes a ring gasket, flat face takes a full-face gasket. Cut cleanly, keep the faces free of old gasket and dirt, and torque in stages and in a cross pattern. Replace the gasket every time the joint is opened.

Frequently Asked Questions

How do I know a gasket is asbestos-free?

Buy to ASME B16.21 and ask for the material data sheet — compliant sheets list their fiber and binder and state asbestos-free. Avoid unmarked legacy stock.

What replaced asbestos in gasket sheets?

Aramid (Kevlar), glass, cellulose and carbon fibers in nitrile, SBR or EPDM binders, plus pure PTFE and graphite sheets.

Where are non-metal sheets not suitable?

High pressure, heavy thermal cycling or severe hydrocarbon service calls for spiral wound or metal gaskets instead.