Spiral wound, ring joint and sheet gaskets
Spiral wound, ring joint, kammprofile and non-asbestos sheet gaskets to ASME B16.20 and B16.21.
Overview
The gasket is the smallest and cheapest part of a flanged joint, and the one that leaks when it is wrong. We supply gaskets matched to the flange standard, class, facing and service temperature, so that valves, flanges, gaskets and bolting arrive as a complete, compatible set.
Spiral wound gaskets to ASME B16.20 with graphite or PTFE filler and 316 or Inconel windings are the standard for raised-face flanges in hydrocarbon and steam service. Ring-type joint gaskets in R oval and octagonal, RX and BX profiles seal high-pressure RTJ flanges on wellheads, pipelines and Class 900 and above. Kammprofile gaskets are supplied for heat exchangers and high-temperature duty, and non-asbestos, PTFE and rubber sheet gaskets for utilities and water.
Every gasket is marked and supplied with a certificate of conformity, and spiral wound and RTJ gaskets with material certification on request.
Typical applications
- Raised-face flanges in refinery and gas plants
- RTJ flanges on wellheads, pipelines and high-pressure piping
- Heat exchanger girth flanges
- Steam and high-temperature lines
- Plant turnarounds and gasket kits
- Water, utility and HVAC flanges
Specified in refineries, fertilizer plants, petrochemicals, power & heavy industry.
Specifications
| Spiral wound (ASME B16.20) | CG / CGI with inner & outer rings · windings 304 / 316L / 321 / Inconel · filler graphite / PTFE / mica |
|---|---|
| Ring type joint (ASME B16.20) | R oval & octagonal · RX · BX · soft iron / low-carbon steel / F5 / 316 / Inconel 625 |
| Kammprofile | Serrated core 316 / Inconel with graphite or PTFE facing, with or without guide ring |
| Sheet & cut gaskets | Non-asbestos (CNAF) · PTFE / ePTFE · graphite · EPDM / NBR / Viton rubber · ASME B16.21 |
| Sizes | ½" – 60" and larger to drawing |
| Pressure classes | ASME 150 · 300 · 600 · 900 · 1500 · 2500 · API 6A |
| Temperature | –200 °C to +550 °C (graphite) / +900 °C (mica) |
| Certification | Certificate of conformity · material certificate on request · fire-safe (API 6FB) grades available |
Sizes, classes and materials listed are typical of our stock and supply programme. Other combinations are quoted against your specification. See what is usually ex-stock.
Specifying the right gasket
The gasket is chosen to the flange, the fluid and the temperature. For raised-face flanges in process service the spiral-wound gasket to ASME B16.20 is the standard: 316 stainless winding with a flexible-graphite filler, a carbon-steel outer centring ring and, for Class 600 and above, an inner ring to prevent buckling. PTFE filler replaces graphite on strongly oxidising or chemical service. For Class 900 and above and RTJ flanges, specify ring-type joint gaskets: R (oval or octagonal) for standard grooves, RX and BX pressure-energised rings for wellhead and API 6A flanges, in soft iron, low-carbon steel, F5, 304 or 316 to suit the flange hardness and the fluid.
Kammprofile (grooved metal with graphite facing) gaskets give the tightest seal on heat exchangers and large-diameter flanges where spiral-wound gaskets struggle. Compressed non-asbestos (CNAF) sheet to ASME B16.21 and PTFE sheet cover utility, water and low-pressure chemical service, and flat-face flanges. Always match the gasket ring to the flange standard (B16.5 or B16.47 A/B) and class, and state the winding and filler material: the same size gasket with the wrong filler will fail on the first thermal cycle.
What to send us for a fast quote
- Gasket type: spiral wound, RTJ (R/RX/BX), kammprofile, sheet
- Flange size, class and standard (B16.5, B16.47 A/B, API 6A)
- Winding / ring material and filler
- Inner ring required (Class 600+ spiral wound)
- Service temperature and fluid
- Quantity and documents required
Why tenders get rejected, and how we avoid it
Gasket lines on Pakistani tenders are checked for the standard (ASME B16.20 or B16.21), the material of winding and filler, and the manufacturer. Bids that quote a generic "SS/graphite" gasket without the inner ring or without the manufacturer's certificate are marked incomplete. We quote to the standard with the manufacturer named and a certificate of conformity per batch. More on API licences, authorisation letters and certificates.
Documentation supplied
EN 10204 3.1 material test certificate traceable to heat number, mill test certificate and dimensional report, certificate of origin and manufacturer's certificate of conformity, with NACE, fire-safe, 3.2 and third-party inspection documents where the order requires them. What every document in our package covers.
Frequently asked questions
Which gasket for a Class 150 RF flange in hydrocarbon service?
A spiral wound gasket with 316L winding, graphite filler and carbon steel outer ring is the normal specification, with an inner ring for sizes where ASME B16.20 requires it.
RX or BX ring gasket?
R and RX rings fit ASME B16.5 / B16.47 RTJ flanges; RX is a pressure-energised version of R. BX rings are for API 6A wellhead flanges 5,000 psi and above and are not interchangeable with R or RX.
Can you supply gasket kits for a shutdown?
Yes, kitted and labelled by line number from your gasket schedule, including bolts and nuts if required.
Spiral wound or kammprofile?
Spiral wound for standard flanged joints to Class 2500: low cost, forgiving of flange condition. Kammprofile for heat exchangers, large flanges and joints that are opened and reassembled often: it needs lower bolt load, tolerates flange damage and seals tighter at high temperature.
Graphite or PTFE filler?
Graphite for hydrocarbons, steam and most process service to about 450 °C. PTFE for oxidising chemicals, strong acids and caustic, and for lines where graphite could contaminate the product, up to about 260 °C.
Related products
Gaskets go with flanges and stud bolts; see those pages, or send us the flange list and we will quote the complete joint.
Flanges
Weld neck, slip-on, blind, socket weld, threaded and lap joint, Class 150 to 2500, RF and RTJ.
Sizes, classes and brands
Stud bolts & fasteners
Stud bolts and heavy hex nuts: B7 / 2H, B7M, B8M, L7, plain, galvanized and PTFE coated.
Sizes, classes and brands
Pipe fittings
Butt-weld elbows, tees and reducers to B16.9; forged socket-weld and threaded fittings to B16.11.
Sizes, classes and brands
Butterfly valves
Resilient, double offset and triple offset designs, 2" to 72", wafer, lug and flanged.
Sizes, classes and brandsRequest a quotation for gaskets
Send size, class, material, quantity and required documents on WhatsApp or through the form. We reply within one working day with availability and lead time.