BLUESEAL ULTRA 350 —
aramid/NBR sheet for documented demanding service
BLUESEAL ULTRA 350 is an aramid/NBR grade to assess where the exact medium, temperature or required gas, oxygen or other documentation rules out a standard-duty cellulose sheet. The current batch-linked document, compatibility check and complete joint design still decide suitability.
Documentation scope: Approval, compliance and certification references apply to the documented material grade, supplier certificate or listing, and stated test conditions unless a product-specific certificate says otherwise. A cut gasket size is not automatically certified as a separate product just because it is made from a documented material. For regulated applications, confirm the current certificate or listing scope, exact grade, medium, temperature, pressure and market requirement before specifying.
Selection rule: BLUESEAL is selected for the medium, approval or higher thermal duty — not to hide a poor face.
Use this when: the exact supplied grade, report scope and compatibility review support the gas, oxygen, chemical, oil, fuel or higher-temperature duty, and the complete joint remains within its design envelope.
Do not use this when: do not use it as a repair for a damaged, worn or uneven mating face. That is a face problem, not a medium problem.
Move away from BLUESEAL when: the face itself is the limitation, move toward FLEXSEAL; when steam or thermal cycling dominates, check GRAPHITESEAL.
What it is
BLUESEAL ULTRA 350
Source boundary: two mapped technical sheets support the core thermal and mechanical values, but their approval-reference lists are not identical: one lists ABS and DNV while the other lists different marine references. Use only the current batch-linked document required by the project. Published temperature and pressure maxima are separate limits, not one operating point.
BLUESEAL ULTRA 350 is a general-purpose aramid fibre gasket material with inorganic fillers and NBR binder. The supplier describes the aramid-based formulation as chemically stable and resistant to creep. That is material-level guidance: compatibility still has to be checked for the exact chemical, concentration, temperature, pressure and exposure time.
Where a standard-duty cellulose grade no longer satisfies the verified medium, temperature or documentation requirement, BLUESEAL is one aramid-based option to assess. Gas, oxygen, chemicals, oils and fuels each require their own compatibility and document check; the material family name is not approval for all of them.
Residual-stress evidence: the fuller mapped grade data reports 27 MPa after 16 hours at 175°C and 23 MPa after 16 hours at 300°C under DIN 52913 test conditions. Those values are useful for comparing exact grades; they do not by themselves predict retained load in a different joint.
Why aramid — and why it matters for your application
Aramid fibre is a synthetic fibre with exceptional tensile strength and thermal stability. In a gasket matrix, aramid fibres create a stiffer, more dimensionally stable material than cellulose — one that resists deformation under sustained load and temperature.
The practical consequence is lower creep relaxation. The mapped cellulose comparison grade has a lower published continuous-temperature range and lower residual-stress data than the mapped aramid grade. Compare those exact grade values and the joint calculation rather than treating all cellulose and aramid materials as two universal performance classes.
BLUESEAL — aramid
- Lower creep under sustained temperature
- Higher tensile strength — 12 MPa
- Listed for a wider media range — verify the exact fluid
- DIN 52913 residual stress: 23 MPa after 16 h at 300°C under the source test conditions
- Source maxima: 350°C short-term and 250°C continuous; verify the combined pressure-temperature envelope
- BAM oxygen-service documentation within the current report scope and stated conditions
- Mapped source references: DVGW, WRAS, SVGW, ABS and DNV — verify the current exact-grade documents
GREENSEAL — cellulose
- Different seating behaviour — compare grade-specific ASTM F36 data
- Different compression and recovery behaviour — check the required seating stress
- Supplier-sheet FDA 21 CFR 175.300 and legacy KTW references — verify current use scope
- Rated to 180°C peak, 140°C continuous
- Standard heating and water service
- Common standard-duty option; compare actual grade cost and service requirements
- Do not extend use beyond the exact documented media and pressure-temperature envelope
The approvals — what each one actually means
BAM
Oxygen-service documentation — a demanding report scope, not a blanket product certification. BAM testing assesses material compatibility with oxygen under defined pressure, temperature and medium conditions, where many organic materials are a fire risk. The mapped BLUESEAL source set lists BAM oxygen-service documentation. Use it only after confirming the current report, exact supplied grade, oxygen conditions, pressure, temperature and report scope.
DVGW
German gas approval — covers both the material standard (DIN 30653 HTB) and the specific leak rate test (DIN 3535-6) for gas service. A key gas-service approval reference for German-market installations and related specification environments.
WRAS
UK potable-water documentation. WRAS is the potable-water signal for UK installations, but use still depends on the listed product or material scope, conditions and maximum water temperature. DVGW and SVGW are the gas-side approvals referenced separately. The mapped source set lists references in both categories; the current document and exact supplied-grade traceability decide whether either claim applies.
SVGW
Swiss gas documentation — a Swiss gas-service reference, analogous in function to DVGW but not interchangeable with it. Relevant where the project or jurisdiction asks for SVGW or Swiss-referenced documentation.
ABS
ABS is listed on one mapped upstream material sheet. Use it only when the supplied material mapping and current ABS document cover the vessel class, thickness and intended service.
DNV
DNV is listed on one mapped upstream material sheet. Confirm the current certificate, supplied material mapping and project scope before making a class claim for a cut gasket.
EC 1935/2004 food-contact compliance documentation is also listed for the material grade. Use still depends on the documented scope, contact conditions, medium, temperature and project requirement.
Who uses it — and why
Gas installers and engineers
DVGW documentation applies to gas service in German-market installations within its stated scope. SVGW covers Switzerland. WRAS is a separate potable water approval for the UK market — it is not a gas signal, while the mapped BLUESEAL source set lists references in both categories. Treat it as a candidate only after the current document, medium-specific scope and supplied-grade traceability have been confirmed.
Chemical and petrochemical industry
The material sheet lists oils, fuels, solvents and several other media. Use that list only as a screening step; final selection requires the exact medium, concentration, temperature, pressure and joint data.
Marine and offshore
One mapped source lists ABS and DNV, while the second lists other marine references. For classed work, request the current batch-linked certificate required by the vessel or project; do not substitute one society's listing for another.
High-temperature industrial
Heat exchangers, steam systems and high-temperature process piping where the selected cellulose grade's published envelope is insufficient. Use the exact grade's temperature, steam, residual-stress and pressure-temperature data as joint-design inputs, not a service-life guarantee.
BLUESEAL vs GREENSEAL — the practical distinction
BLUESEAL is chosen because of the medium. GREENSEAL is chosen because the medium is not the challenge.
Standard domestic and commercial heating at normal temperatures, water service, glycol circuits — GREENSEAL usually covers those applications adequately at a lower material specification level. The moment the medium changes — gas, oxygen, chemicals, high temperature above 140°C continuous — BLUESEAL is usually where the specification moves next.
Field example: a routine heating-water union may remain within a documented cellulose grade. A natural-gas joint requires the seal specified for the fitting or appliance and the applicable gas-service documentation; do not infer approval from the word aramid. A 160°C process joint needs the exact pressure-temperature, gasket-stress and compatibility check before any BLUESEAL decision.
When to use it — and when not to
Where BLUESEAL makes sense
- Gas service — confirm which current approval or report is required by the fitting, project and jurisdiction, then verify that exact scope
- Oxygen service — obtain and verify the applicable BAM report scope, pressure, temperature, medium and cleaning requirements
- Continuous temperature outside the verified envelope of the standard-duty candidate, with the BLUESEAL P-T and joint checks completed
- Chemical service — oils, fuels, solvents
- Marine or offshore work where the current batch-linked class document matches the project
- High-pressure industrial flanges with good face condition
- Long service intervals where creep relaxation must be minimised
- Service where the exact chemical, concentration, temperature and exposure time have been checked against the current grade data
- Clean, serviceable faces with verified geometry, surface finish and available seating load
When BLUESEAL is not the first answer
- Standard heating and water service at normal temperatures — GREENSEAL is usually the simpler and lower-spec option for standard-duty service
- The face is outside acceptance — repair or replace it; do not route damage automatically to a more compressible grade
- Low bolt load fittings where a stiffer gasket requires more force than the joint can safely take
- A simpler documented material fully covers the exact water service and required market scope
Practical notes
Both faces carry anti-stick treatment. At the next service interval, BLUESEAL lifts away from the flange cleanly — less bonded residue, less face damage risk during removal, faster preparation for the replacement gasket. The face still needs inspection and cleaning, but the removal step is significantly easier than with untreated materials.
The material sheet lists 0.5, 1.0, 1.5, 2.0 and 3.0 mm sheet thicknesses. A cut gasket must match the joint's closure geometry and thickness-specific data; do not change thickness simply to compensate for face condition or limited load.
BLUESEAL's published compressibility is 11% under ASTM F36 conditions. That value describes this grade under a defined test; it should not be used by itself to rank stiffness or creep against a different material family. On flanges with adequate bolt load and good face condition, its controlled seating behaviour is useful. On soft-metal fittings with limited bolt load, confirm that the available load can seat the selected grade evenly. If the fitting is old brass or the bolt load is limited, consider whether FLEXSEAL PRO 350 is the more appropriate choice.
Technical sheets and available supplier documents are handled per material line. DVGW, WRAS, BAM, SVGW and conditional EC 1935/2004 references appear across the mapped source set; ABS and DNV appear in one of those source sheets. The current batch-linked document and its scope control any claim. Contact via the B2B page for current documentation requests.
Sizes and packaging
| BSP size | Dimensions (mm) | SKU 25 pcs | SKU 100 pcs |
|---|---|---|---|
| 3/8″ | 14.5 × 9 × 2 mm | B-2014GES32-25 | B-2014GES32-100 |
| 1/2″ | 18.5 × 11 × 2 mm | B-2014GES33-25 | B-2014GES33-100 |
| 3/4″ Normal | 24 × 18 × 2 mm | B-2014GES34-25 | B-2014GES34-100 |
| 3/4″ Special | 24 × 16 × 2 mm | B-2014GES35-25 | B-2014GES35-100 |
| 1″ Normal | 30 × 24 × 2 mm | B-2014GES36-25 | B-2014GES36-100 |
| 1″ Special | 30 × 21 × 2 mm | B-2014GES37-25 | B-2014GES37-100 |
| Box set — 320 pcs — 3/8″ to 1″, 6 sizes | B-2014BOX3 | ||
Custom dimensions and non-standard sizes available on request through B2B contact.
When the medium is demanding, the gasket has to match it. BLUESEAL ULTRA 350 is intended for that service envelope.
Gas. Oxygen. Chemicals. High temperature. Marine. These are duties where approval scope, media compatibility and retained gasket stress need more evidence than a standard-duty material name provides.
BLUESEAL combines aramid/NBR construction with source-listed gas, oxygen and other documentation references that standard cellulose grades may not provide. Chemical suitability still requires the exact medium, concentration, temperature and exposure review. Treat the grade as a candidate only within the verified P-T, gasket-stress, report and joint envelope; repair an unacceptable face instead of switching materials to hide it.