What Is a Metal Jacketed Gasket?
A metal jacketed gasket consists of a soft core (flexible graphite, PTFE or ceramic fibre) enclosed inside a thin metal jacket. The metal jacket contains and protects the soft filler, while the filler provides the low seating stress needed to seal. Jacketed gaskets were widely used on raised-face and tongue-and-groove flanges in older refinery and power piping.
Status in ASME B16.20-2023
Important: in the 2023 edition, ASME B16.20 deleted Part JA (Jacketed Gaskets) — Record 12-517 removed all references to double-jacketed (DJ) gaskets from the standard. Today B16.20-2023 covers three gasket families: spiral-wound gaskets (Part SW), ring-joint gaskets (Part RJ) and grooved metal gaskets with covering layers (Part GM). Jacketed gaskets are now manufactured to the traditional API 601 lineage and purchaser specifications; dimensional values follow the API 601 heritage tables rather than a current B16.20 dimension table.
Construction Types
- Single jacket — one metal layer folded over the soft core
- Double jacket — two nested jackets (removed from B16.20 in 2023; still supplied to API 601 tradition)
- Corrugated / serrated jacket — improves conformity to the flange face
Materials
| Part | Common Materials |
|---|---|
| Jacket | Carbon steel, 304/316 stainless, Inconel, Monel |
| Core | Flexible graphite, PTFE, ceramic / non-asbestos fibre |
Dimensions for a specific flange class: consult API 601 / B16.5 flange dimensions — send us your flange standard, size and class and we will quote the matching jacketed gasket.
Related Standards
- ASME B16.20 — Metallic Gaskets (Parent Standard)
- ASME B16.20 Spiral Wound Gaskets
- ASME B16.20 RTJ Ring Joint Gaskets
- ASME B16.5 — Pipe Flanges (NPS 1/2–24)
- Our Metallic Gasket Range
- ASTM A182 F304 Stainless Steel
FAQ
Does ASME B16.20-2023 still cover jacketed gaskets?
No. Part JA (Jacketed Gaskets) was deleted in the 2023 edition, together with all double-jacketed references. Jacketed gaskets are now supplied to API 601 tradition and purchaser specifications.
Can you still manufacture jacketed gaskets?
Yes — we supply single- and double-jacketed gaskets with graphite or PTFE core for legacy flanges, sized to your flange drawing or API 601 tables.
Jacketed or spiral-wound for new piping?
For new ASME B16.5 flanges we normally recommend spiral-wound gaskets per B16.20, which are the current industry standard; jacketed gaskets remain an option for retrofit and API 601 duty.
What are jacketed gaskets made of?
A soft core (graphite, PTFE or fibre) inside a carbon-steel or stainless-steel jacket, chosen to match the process medium and temperature.
Need This Standard for Your Project?
We manufacture and export flanges, fittings and gaskets to ASME standards. Send your standard, size, material, and quantity — we reply within 24 hours.