GRAPHITESEAL ULTRA 350 —
graphite composite gasket for steam, oxygen-documented service and high-temperature duty
Aramid fibre provides the structural backbone. Lamellar graphite extends the temperature capability and improves performance under thermal cycling. Together, they produce a material suited to service conditions that standard fibre composites are not designed to handle.
Selection rule: GRAPHITESEAL is for heat, steam and thermal cycling where fibre grades reach their limit.
Use this when: steam, boiler duty, oxygen-documented applications, high-temperature industrial service and thermal cycles that punish ordinary fibre gaskets.
Do not use this when: do not use it as a generic upgrade where GREENSEAL or BLUESEAL already matches the medium, face and temperature.
Move to this material when: continuous heat, steam exposure or documented oxygen duty becomes the deciding factor.
What it is
GRAPHITESEAL ULTRA 350
GRAPHITESEAL ULTRA 350 is a compressed fibre gasket material combining aramid fibres, lamellar graphite and an NBR binder. It is the specialist graphite composite in the Kinetics Line range — the material usually specified when temperature, steam rating or thermal cycling severity moves the specification beyond what standard aramid fibre can reliably cover.
Lamellar graphite is the critical addition. In a fibre matrix, graphite contributes to higher temperature capability and improved behaviour in steam and thermally demanding service — including conditions where organic binders in standard fibre composites begin to degrade. The aramid fibre reinforcement provides the structural backbone: dimensional stability, tensile strength and resistance to the bolt load effects that can occur in high-temperature flanges. Neither component alone produces the performance combination the material delivers together.
Temperature range — what each rating means
Peak and continuous temperatures are not for simultaneous use with maximum pressure. Allowable pressure decreases as temperature increases. Consult technical data for the combined operating envelope.
The steam rating of 250°C is the key differentiator from standard aramid fibre. Steam carries high heat energy, causes rapid thermal cycling, and the phase transition between water and steam creates additional mechanical stress at the joint face. BLUESEAL ULTRA 350 is rated to 200°C steam. GRAPHITESEAL extends that to 250°C — the 50°C margin is the technical reason it is specified for high-pressure steam systems where BLUESEAL is at or beyond its rated limit.
Thermal limits — interactive reference
Set the system temperature and medium below to see which materials remain within their rated operating limits.
Why graphite — what it adds over standard aramid
GRAPHITESEAL ULTRA 350
- Continuous service to 280°C
- Steam to 250°C
- BAM approved for oxygen-documented service
- BS 7531 Grade Y — UK industrial standard
- DIN 28091 — German industrial flanges
- Anti-stick on one face
- For steam lines, boilers, power plant, O₂ service
BLUESEAL ULTRA 350 — Aramid only
- Continuous service to 250°C
- Steam to 200°C
- DVGW, WRAS, BAM, SVGW, ABS, DNV approved
- Anti-stick on both faces
- Better chemical resistance profile
- For gas, chemicals, oils, general industrial
- Usually considered first below 200°C steam
BLUESEAL or GRAPHITESEAL? The deciding factor is usually steam temperature and thermal cycling severity. BLUESEAL is rated to 200°C steam. GRAPHITESEAL is rated to 250°C. If the system cycles repeatedly between ambient and operating temperature — as boilers and heat exchangers do — graphite generally performs more consistently over the service life. If the system does not exceed 200°C steam and oxygen service is not a requirement, BLUESEAL usually covers the application.
Approvals
BAM
Bundesanstalt für Materialforschung, GermanyBAM oxygen-service documentation. The report scope must be checked against the tested pressure, temperature, oxygen medium and test conditions before specifying for oxygen pipelines, cylinders or medical gas systems.
Oxygen serviceDIN 28091
German Institute for StandardisationDefines requirements for non-metallic flat gaskets for industrial flanges. Compliance confirms the material meets dimensional, mechanical and functional requirements for standard flanged joint applications in German industrial practice.
Industrial flangesBS 7531 Grade Y
British Standard — compressed fibre gasketsGrade Y is the higher performance classification under BS 7531. Covers steam, hot water, oils and chemical media. Specifying BS 7531 Grade Y is common in UK industrial and process engineering procurement.
UK industrial standardNon-asbestos
Asbestos-free compositionAramid fibre, lamellar graphite and NBR binder only. Relevant for procurement compliance in industries where asbestos-free documentation is required for material qualification.
Asbestos-freeWhere GRAPHITESEAL ULTRA 350 is specified
- Steam lines and high-temperature piping — continuous steam service, high-pressure steam distribution, process steam systems above 200°C
- Boilers and heat exchangers — repeated thermal cycling, high joint face temperatures, conditions where standard aramid fibre approaches its rated limit
- Oxygen service — assess against the BAM report scope for the tested pressure, temperature, oxygen medium and conditions
- Chemical and petrochemical plant flanges — alkalis, oils, fuels at elevated temperature and pressure within the rated envelope
- Power plant equipment — turbine connections, high-pressure valves, process isolation flanges
- BS 7531 Grade Y specified procurement — any application where Grade Y is called out in the specification or purchase order
- Dynamic load applications — joints subject to vibration, pressure fluctuation or repeated assembly and disassembly at elevated temperature
Not for potable water service. For UK WRAS-required drinking-water applications, specify REDSEAL PRO 110 or BLUESEAL ULTRA 350 within their listed scope. Where FDA documentation or KTW/UBA references are the requirement, GREENSEAL PRO 180 is the relevant water-contact grade. GRAPHITESEAL ULTRA 350 is not the material for potable-water service.
GRAPHITESEAL vs BLUESEAL — when to specify which
Consider GRAPHITESEAL when
- Steam above 200°C continuous
- Continuous service above 250°C
- Oxygen service — BAM report scope required and checked
- BS 7531 Grade Y specified in procurement
- Severe thermal cycling — boilers, heat exchangers
- Power plant or heavy industrial service
- Dynamic loads with vibration at elevated temperature
Consider BLUESEAL when
- Gas lines — DVGW or SVGW approval required
- Chemical and solvent resistance is the priority
- Steam below 200°C continuous
- WRAS approval required for potable water
- Anti-stick on both faces is preferred
- The application does not require the higher steam or oxygen rating
Anti-stick coating — one face
GRAPHITESEAL ULTRA 350 carries anti-stick surface treatment on one face. This reduces adhesion between the gasket and the flange face after service at high temperature — a practical consideration when the gasket has been in steam service at 250°C and the joint needs to be broken for maintenance.
Graphite-based materials can bond to flange faces under sustained high-temperature service. The anti-stick treatment reduces this tendency. It does not eliminate it entirely — gaskets that have been in extended steam service at elevated temperature may still require careful removal — but the risk of face damage on disassembly is reduced. For orientation guidance in critical joints, consult the technical datasheet.
Sizes and packaging
| BSP size | Dimensions (mm) | SKU 25 pcs | SKU 100 pcs |
|---|---|---|---|
| 3/8″ | 14.5 × 9 × 2 | B-2014GES43-25 | On request |
| 1/2″ | 18.5 × 11 × 2 | B-2014GES44-25 | On request |
| 3/4″ Special | 24 × 14.5 × 2 | B-2014GES45-25 | On request |
| 1″ | 30 × 21 × 2 | B-2014GES45A-25 | On request |
| 1¼″ | 39 × 30 × 2 | B-2014GES45AB-25 | On request |
| 1½″ | 44.5 × 36 × 2 | B-2014GES45AC-25 | On request |
| Box set 3/8″ to 1″ — 300 pcs, 6 sizes | B-2014BOX7 | ||
100 pcs packs available on request for individual sizes. Custom dimensions and sheet material available through B2B contact. Standard thickness 2 mm across all BSP sizes.
GRAPHITESEAL ULTRA 350 is the specialist graphite composite in the Kinetics Line system — for steam, oxygen service and high-temperature industrial applications where standard aramid fibre is not rated for the operating conditions.
The combination of lamellar graphite and aramid fibre gives it the steam temperature rating, the thermal cycling stability and the BAM oxygen-service documentation that the standard aramid series does not carry. For service conditions below 200°C steam and without an oxygen service requirement, BLUESEAL usually covers the application. For service conditions at the demanding end of the range, GRAPHITESEAL is usually the next material considered in the specification.