Rubber Steel Flange Gaskets Manufacturer & Global Exporter
Vulcanized EPDM and NBR rubber-to-steel reinforced flange gaskets certified under German UBA KTW-BWGL, DVGW W270, and DIN EN 681-1.
45,000 sq.ft customs-bonded facility equipped with 50T–500T vacuum moulding presses, in-house mixing mills, and Class 5/7 cleanrooms.
Precision Polymer Engineering for Critical Industrial Operations
Rubber steel gaskets combine the high mechanical stability and blow-out resistance of an internal steel core with the low seating stress and elastic sealing properties of vulcanized elastomeric beads. Manufactured at our Chennai MEPZ-SEZ facility, our gaskets feature a corrugated or flat carbon steel (or 304/316 stainless) insert completely encapsulated in vulcanized EPDM or NBR rubber, preventing media contact with the metal reinforcement.
For municipal drinking water applications, our EPDM rubber-steel gaskets comply with the latest German Federal Environment Agency (Umweltbundesamt) KTW-BWGL guidelines and DVGW Worksheet W270. Stringent laboratory testing confirms zero migration of toxic plasticizers, organoleptic neutrality, and complete resistance to microbial biofilm slime growth inside pressurized potable water mains.
In natural gas and hydrocarbon distribution lines, Horiaki NBR rubber-steel gaskets conform to DIN EN 682, delivering superior resistance to gas permeation, condensates, and explosive decompression. The internal corrugated steel ring concentrates bolt loading onto the raised sealing crown, achieving tight Class A sealing at 40% lower bolt torque than conventional flat sheet gaskets—eliminating flange warping on plastic (HDPE, PVC, GRP) and ductile iron flanges.
Key Features & Performance Advantages
Formulated and tested to meet international ASTM, DIN, and ISO elastomeric criteria.
German UBA KTW-BWGL Drinking Water Approval
Certified migration compliance under the mandatory German drinking water ordinance, ensuring safe, non-toxic potable water distribution.
DVGW W270 Microbial Resistance Verification
Surface biofilm prevention testing proves zero microbial growth, slime formation, or bacterial proliferation in warm and cold water pipelines.
Corrugated Core High Blow-Out Safety (> 100 Bar)
Internal corrugated carbon or stainless steel core prevents gasket blowout even under severe pressure surges and water hammer.
40% Lower Bolt Seating Torque
Concentrated convex elastomeric sealing lips seal effectively at low bolt loads, protecting fragile plastic (HDPE / GRP) and coated flanges.
Self-Centering Outer Ring Geometry
Precision outer ring dimensions center the gasket automatically against flange bolts, preventing installation misalignment and flow restriction.
Total Encapsulation & Corrosion Barrier
Vulcanized rubber completely encapsulates the internal steel core, preventing galvanic corrosion and atmospheric degradation.
Technical Specifications & Compound Grades
All compound properties validated on in-house MDR Rheometer and computerized UTM tensile rigs.
| Compound Grade / Parameter | Hardness | Tensile Strength | Elongation | Compression Set | Operating Temp | Certified Standards |
|---|---|---|---|---|---|---|
| HK-RSG Water (EPDM / KTW-BWGL / W270) | 70 ± 5 Shore A | 14.5 MPa | 280% | < 20% (72h @ 23°C) | -30°C to +110°C | German KTW-BWGL, DVGW W270, EN 681-1 |
| HK-RSG Gas (NBR / DVGW EN 682) | 70 ± 5 Shore A | 15.0 MPa | 260% | < 22% (72h @ 23°C) | -20°C to +90°C | DIN EN 682 (Type GBL Gas Supply) |
| HK-RSG Solar/Hot (FKM Viton Encapsulated) | 75 ± 5 Shore A | 16.0 MPa | 220% | < 18% (22h @ 150°C) | -15°C to +200°C | High Temperature Chemical & Solar Oil |
| Steel Reinforcing Core Specifications | N/A (Steel Core) | > 350 MPa | > 20% | Zero Plastic Deflection | Up to +500°C Core Rating | Carbon Steel DC01 or Stainless 304/316 |
Standard Tooling: We maintain complete in-house molds for standard international sizes (AS568, ISO 3601, DIN EN 1092-1, ASME B16.5) for rapid production.
Made-To-Order: Require non-standard dimensions, custom shore hardness, special color pigmentation, or tailored chemical resistance? Our in-house toolroom manufactures custom multi-cavity tooling in 7 business days.
Industrial Applications & Operating Equipment
Deployed in severe industrial environments requiring long-term reliability and zero fluid escape.
1Municipal Drinking Water Transmission Mains
Specific Use-Case: Ductile iron, steel, and HDPE pipe flange connections in municipal treatment plants and trunk distribution pipelines.
Potable drinking water at PN 10 to PN 25 operating pressures under continuous disinfection.
2Natural Gas & Biogas Distribution Networks
Specific Use-Case: District gas regulation stations, city gas distribution pipelines, and metering skids requiring zero gas permeation.
Dry natural gas, odorized methane, LPG, and biogas at operating pressures up to PN 16 / PN 40.
3Wastewater Treatment & Desalination Plants
Specific Use-Case: Seawater reverse osmosis (SWRO) intake headers, brine reject piping, and activated sludge aerator manifolds.
High chloride seawater and aggressive sewage chemicals resisting biological degradation.
4Chemical Pipeline Flanges & Industrial Cooling
Specific Use-Case: Process water cooling loops, low-pressure steam condensates, and dilute acid/alkali piping.
Cyclic thermal expansion and contraction with frequent pressure fluctuations.
Industries Served Globally
Supplying tier-1 OEMs and plant engineering contractors across 75+ export corridors.
Supplying European water utilities with KTW-BWGL and DVGW W270 certified gaskets meeting strict Trinkwasser standards.
Providing EN 682 approved NBR rubber-steel gaskets with high blowout safety for city gas networks.
Corrosion-proof encapsulated gaskets with stainless 316 steel cores for high-salinity reverse osmosis piping.
Full inventory of standard DIN EN 1092-1 (DN 15 to DN 2000) and ASME B16.5 (1/2" to 48") dimensions.
In-House Manufacturing Infrastructure
Integrated compounding, rapid CNC die machining, and cleanroom vacuum molding.
In-house progressive dies producing uniform wave corrugation for concentrated sealing load.
High-tonnage multi-platen vacuum presses ensuring 100% void-free rubber-to-steel encapsulation.
Video measuring machine (VMM) verifying concentricity, bolt circle alignment, and lip heights.
In-house flange test rig validating blowout safety exceeding 100 bar on DN 100 test samples.
Technical Selection Criteria
Essential engineering parameters to verify prior to specifying components for production tooling:
For potable water, specify EPDM with KTW-BWGL & DVGW W270; for gas/petroleum, specify NBR per DIN EN 682.
On PE, PP, or PVC flanges, the lower bolt torque of rubber-steel gaskets prevents flange distortion and cracking.
Match flange rating: PN 10, PN 16, PN 25, or PN 40 per DIN EN 1092-1; Class 150/300 per ASME B16.5.
Specify corrugated core (G-ST) for highest blowout resistance and lowest required bolt torque.
Information Required for Technical Quotation
To expedite quotation turnaround within 24 hours, overseas procurement engineers should provide:
- Nominal Pipe Size: Metric (DN 15 to DN 2000) or Imperial (1/2" to 48").
- Flange Standard & Pressure Class: DIN EN 1092-1 (PN 10 / PN 16 / PN 25 / PN 40) or ASME B16.5 (Class 150 / 300).
- Elastomer Compound: EPDM (drinking water / KTW / DVGW W270) or NBR (gas / hydrocarbons / EN 682).
- Steel Core Material: Carbon steel galvanized or Stainless Steel AISI 304 / 316.
- Required order quantity and target destination seaport for ocean freight quotation.
Frequently Asked Questions
Common questions regarding compound formulations, tooling lead times, and export logistics.
Why are KTW-BWGL and DVGW W270 certifications critical for water pipeline gaskets in Europe?
The German KTW-BWGL guideline is legally mandated across the EU to ensure that elastomeric materials do not leach harmful organic chemicals into drinking water. DVGW W270 certifies that the rubber surface does not support microbial or bacterial growth (biofilm), protecting public health.
Can rubber steel gaskets be installed on HDPE stub ends without backing rings?
Rubber steel gaskets are ideal for HDPE pipe stub ends because the internal steel core provides uniform circumferential load distribution, allowing effective sealing at low bolt torques without crushing the plastic stub end.
How do rubber steel gaskets prevent blowout under pressure surges?
The vulcanized rubber is mechanically bonded to the internal corrugated steel ring. Even during intense water hammer or pressure spikes exceeding 100 bar, the rigid steel core cannot be displaced, preventing catastrophic gasket extrusion.
What is the recommended bolt tightening torque for rubber steel gaskets?
Because of the raised convex elastomeric sealing bead, rubber steel gaskets achieve tight sealing at approximately 50% to 60% of the bolt torque required by standard fiber or PTFE sheet gaskets (e.g., DN 100 PN 16 requires only 85 Nm).
How are export shipments dispatched from Chennai to European seaports?
Gaskets are packed flat with edge protectors inside heavy export cartons, stacked on ISPM-15 certified heat-treated wooden pallets, shrink-wrapped, and loaded into ocean containers at Chennai Port (INMAA) with direct sailings to Hamburg/Rotterdam in 24–28 days.
Direct Ocean Transit from Chennai Port (INMAA)
Weekly scheduled FCL and LCL container sailings under customs-bonded MEPZ-SEZ export sealing.
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Ready to Request Quotations for Rubber Steel Gaskets?
Submit your engineering drawings and volume requirements. Our polymer application team will respond with full technical datasheets and competitive export pricing within 24 hours.