LEADING METAL GASKETS MANUFACTURER, EXPORTER & SUPPLIER
Manufacturer, Exporter & Supplier of Premium Industrial Gaskets
All Types of Industrial Copper Gaskets — Precision Manufactured in Pure Copper for Heat Exchangers, Engine Systems & Process Equipment
Sunflex Metalloy is a precision manufacturer of industrial Copper gaskets — supplying all major gasket types in commercially pure copper grades C10100, C10200, and C11000 to the heat exchanger manufacturing, automotive and marine engineering, HVAC and refrigeration, power generation, hydraulic systems, and general process industries. From soft annealed flat ring gaskets to precision-machined Lens Ring, Ring Type Joint (RTJ), Spiral Wound, Kammprofile, Corrugated, Metal Jacketed, and Solid Metal designs, we manufacture the complete range of copper sealing solutions to ANSI, ASME, DIN, BS, and custom standards — in both standard and fully custom dimensions.
Copper's extraordinary combination of thermal conductivity, natural malleability, corrosion resistance in water and atmospheric environments, and ability to cold-flow under bolt compression to conform to flange surface irregularities makes it the preferred gasket material in applications where heat transfer performance, soft conformable sealing, or electrical continuity at the flange joint are critical requirements. Every Sunflex Metalloy copper gasket is manufactured from certified raw material, dimensionally inspected, and available with full material test certificates (MTC) as per EN 10204 3.1 or 3.2.
Grades Available: C10100 (OFC) · C10200 (OF Copper) · C11000 (ETP Copper) · ASTM B152 · ASTM B187
Copper is one of the oldest engineering materials known to industry — and its continued widespread use in industrial gaskets is a testament to its genuinely exceptional combination of physical and mechanical properties. The defining characteristic of copper as a gasket material is its natural softness and malleability. Unlike harder metals such as stainless steel or carbon steel, copper cold-flows under bolt compression — meaning it plastically deforms at relatively low seating stresses to fill and conform to the microscopic surface irregularities of the mating flange faces, creating a leak-tight seal even where the flange surface finish is less than perfect.
Beyond its soft sealing capability, copper's thermal conductivity — approximately 16 times higher than stainless steel — makes it the material of choice in heat exchanger applications where the gasket must not insulate the joint or impede heat transfer. Its natural resistance to freshwater, atmospheric, and mild chemical corrosion ensures long service life in water systems, HVAC circuits, and general process piping. Its high electrical conductivity makes it the preferred gasket material in electrical equipment, transformer connections, and earthing applications. And its compatibility with steam, oil, compressed air, and a wide range of mild industrial fluids makes it a genuinely versatile sealing solution for general industry.
Sunflex Metalloy manufactures copper gaskets across three primary grades — Electrolytic Tough Pitch (ETP) copper C11000, Oxygen-Free Copper (OFC) C10100, and Oxygen-Free Copper C10200 — each offering a slightly different balance of conductivity, purity, and fabricability. All copper gaskets can be supplied in the annealed (soft) condition for maximum conformability, or in the as-rolled condition where greater dimensional rigidity is preferred during handling and installation.
| Grade | UNS | Purity | Key Properties | Typical Application |
|---|---|---|---|---|
| ETP Copper | C11000 | 99.9% Cu | Most widely used, excellent conductivity | General industrial gaskets, heat exchangers, HVAC |
| OF Copper | C10200 | 99.95% Cu | Oxygen-free, higher purity | Electrical applications, precision instruments |
| OFC Copper | C10100 | 99.99% Cu | Ultra-high purity, maximum conductivity | Electronics, semiconductors, high-spec electrical |
Sunflex Metalloy manufactures all eight major copper gasket types — each engineered for specific sealing requirements, flange face configurations, pressure classes, and thermal or mechanical performance demands.
Soft Metal RTJ Sealing for Low-to-Medium Pressure Flanges in Water, Steam & General Process Service
Copper Ring Type Joint (RTJ) gaskets are precision-machined solid copper sealing rings designed for use with RTJ flange faces — delivering a reliable metal-to-metal seal through the natural ductility and malleability of the copper material. When installed in the trapezoidal groove of an RTJ flange and torqued to specification, the copper ring deforms plastically into the groove walls under bolt load, creating an intimate, conforming metal-to-metal contact seal.
Copper RTJ gaskets are primarily used in lower-pressure process and utility flanges — water systems, steam utility lines, general process piping, and HVAC applications — where the RTJ flange configuration has been specified for operational or standardization reasons but where the extreme high-pressure capability of harder metallic rings is not required.
Resilient Semi-Metallic Copper Sealing for Cyclic Thermal Service & Heat Transfer Applications
Copper Spiral Wound gaskets are semi-metallic sealing elements constructed by spirally winding a thin copper metallic strip alternately with a soft filler material — typically PTFE or flexible graphite — to produce a resilient, self-energizing gasket assembly. The copper winding strip provides thermal conductivity, corrosion resistance, and material compatibility advantages in a spirally wound format.
Copper spiral wound gaskets are particularly valuable in heat exchanger and thermal process applications where the high thermal conductivity of the copper winding strip minimizes thermal resistance at the flanged joint and supports heat transfer performance across the sealing interface. Available with SS 304 or SS 316 inner and outer rings for dimensional stability.
Multi-Line Soft Metal Sealing with Low Seating Stress for Heat Exchangers & Delicate Flange Assemblies
Copper Corrugated Metal gaskets are manufactured by forming a precision copper sheet into a series of concentric corrugations across the gasket face — creating multiple raised contact ridges that concentrate the bolt load onto narrow sealing lines while significantly reducing the total seating stress required. The soft, ductile nature of copper means the corrugation ridges deform readily under bolt compression, conforming closely to the mating flange surface and creating multiple parallel sealing lines.
The combination of copper's inherent softness, multi-line sealing geometry, and excellent thermal conductivity makes corrugated copper gaskets well-suited for heat exchanger flanges, refrigeration system connections, and general process equipment. Available plain (bare copper) or with PTFE overlay on both faces for enhanced conformability and chemical resistance.
Conformable Soft-Fill Sealing with Pure Copper Jacket for Heat Exchangers & General Process Equipment
Copper Metal Jacketed gaskets consist of a soft, compressible filler core — typically flexible graphite, compressed non-asbestos fibre (CNAF), ceramic fibre, or PTFE sheet — enclosed within a formed pure copper metal outer jacket. The copper jacket provides the outer sealing surface, mechanical protection for the soft filler, and resistance to the process fluid and environment.
The natural ductility and softness of the copper jacket means it deforms readily under bolt compression, conforming to minor flange surface imperfections. Copper jacketed gaskets are particularly valued in heat exchanger channel cover applications — where the large gasket diameter, moderate pressure, and heat transfer requirements all favour the copper jacket material. Available in single-jacketed and double-jacketed configurations.
Pure Copper All-Metal Sealing for Maximum Conformability, Thermal Performance & Long-Life Service
Copper Solid Metal gaskets are manufactured entirely from solid copper bar, rod, or sheet — no composite layers, no filler material, no bonded components. The all-copper, single-material construction delivers maximum conformability and thermal performance. The natural ductility of copper allows solid copper gaskets to cold-flow under bolt compression, conforming intimately to the mating flange surface and creating a leak-tight metal-to-metal seal without requiring excessive bolt load.
Solid copper gaskets are the most widely used copper gasket form across general industry — found in heat exchanger connections, marine engine systems, steam utility flanges, hydraulic equipment, electrical panel sealing, and a broad range of general process applications. Sunflex Metalloy manufactures solid copper gaskets in flat ring, full-face, and custom-profile forms from C11000 ETP copper and C10100 / C10200 oxygen-free grades.
Precision Spherical Copper Sealing for High-Pressure Hydraulic & Instrumentation Connections
Copper Lens Ring gaskets are precision-machined solid copper sealing rings with a convex spherical cross-section profile — the defining geometry that gives this gasket type both its name and its unique sealing mechanism. The convex spherical profile contacts the matching concave conical seat in the mating flange or fitting face at a single circular line of contact, concentrating the bolt or connection load onto a very narrow sealing area to generate high contact stress.
The copper lens ring's ability to achieve excellent sealing at lower assembly loads — a direct result of the material's inherent softness — makes it particularly well-suited to hydraulic systems, instrumentation connections, and high-pressure piping applications. Copper lens rings are also widely used as crush seals in hydraulic fittings, where the copper deforms permanently under assembly torque to create a reliable, non-leaking connection. Manufactured to DIN 2696 and custom specifications, CNC-machined from certified copper bar.
Soft Copper RTJ Ring Seals for Low-to-Medium Pressure Water, Steam & General Process Flanges
Copper Octagonal and Oval Ring gaskets are solid copper sealing rings designed for use with Ring Type Joint (RTJ) flanges — delivering the metal-to-metal sealing capability of the RTJ design combined with the soft, conformable sealing characteristics unique to copper. Both profiles seat into the precision-machined trapezoidal groove of an RTJ flange and create a seal through controlled plastic deformation of the copper ring under bolt load.
The Oval Ring profile with its rounded cross-section is the more traditional copper ring form — widely used as a replacement or maintenance gasket in legacy RTJ flange systems. The Octagonal Ring profile, with its flat-sided geometry and greater groove contact area, is preferred for higher-pressure applications and new installations. Both profiles are manufactured in C11000 ETP copper in the annealed condition, across all API standard ring numbers and in custom dimensions.
Precision-Grooved Copper Core with Soft Overlay — Superior Sealing for Heat Exchangers & Thermal Process Flanges
Copper Kammprofile gaskets feature a solid copper metal core with precision-machined concentric serrated grooves on both faces, covered with a bonded soft overlay of PTFE or flexible graphite. The combination of the grooved copper core and the soft overlay creates a gasket that delivers outstanding sealing performance — the serration ridges concentrate bolt load onto multiple high-stress sealing lines, while the soft overlay fills surface imperfections and provides a chemical barrier between the copper core and the process fluid.
The use of copper as the Kammprofile core material brings specific advantages in heat exchanger and thermal process applications. Copper's exceptionally high thermal conductivity minimizes thermal resistance at the flanged joint, supporting overall heat exchanger efficiency. The solid copper core is reusable — only the soft overlay needs replacement at maintenance, significantly reducing long-term gasket replacement costs.
Match your operating conditions, flange type, and pressure class to the right copper gasket form:
| Gasket Type | Pressure Class | Temp Range | Flange Face Type | Reusable | Best Application |
|---|---|---|---|---|---|
| Ring Type Joint (RTJ) | Class 600–2500 | Up to 300°C | RTJ Groove | No | Water, steam, general process RTJ flanges |
| Spiral Wound | Class 150–2500 | Up to 350°C | RF, FF, T&G | No | Heat exchangers, thermal process piping |
| Corrugated Metal | Class 150–900 | Up to 300°C | RF, FF | No | Low bolt load flanges, heat exchangers |
| Metal Jacketed | Class 150–900 | Up to 350°C | FF, RF, MF, T&G | No | Heat exchanger covers, large flanges |
| Solid Metal | Class 150–2500 | Up to 350°C | All types | No | General process, heat exchangers, engines |
| Lens Ring | Ultra-high pressure | Up to 300°C | Concave conical seat | No | Hydraulic fittings, instrumentation |
| Octagonal / Oval Ring | Class 600–2500 | Up to 300°C | RTJ Groove | No | Legacy RTJ systems, soft-metal replacement |
| Kammprofile | Class 150–2500 | Up to 350°C | RF, FF, MF, T&G | Yes (core) | Heat exchangers, thermal process vessels |
With a thermal conductivity of approximately 385 W/m·K — roughly 16 times higher than austenitic stainless steel — copper is by far the most thermally conductive common gasket metal. In heat exchanger applications, a copper gasket introduces minimal thermal resistance at the flanged joint, supporting heat transfer performance.
Copper's low hardness and high ductility allow it to cold-flow under bolt compression — conforming to flange surface irregularities and creating a leak-tight seal even where the flange surface finish does not meet the ideal specification. Copper gaskets are tolerant of aged, worn, or imperfect flange faces.
Copper develops a natural protective patina — a stable surface film of copper oxide and carbonate — that provides long-term resistance to freshwater, potable water, atmospheric, and mild chemical corrosion. Suitable for water supply systems, HVAC circuits, and cooling water piping.
Copper gaskets are compatible with steam, hot and cold water, lubricating oil, hydraulic oil, compressed air, and a wide range of refrigerants used in HVAC and refrigeration systems — making them a practical, widely applicable general-purpose soft metal gasket material.
Copper's high electrical conductivity makes it the preferred gasket material wherever electrical continuity at the flanged joint is required — including transformer connections, bus bar jointing, electrical panel sealing, earthing connections, and EMI shielding applications.
Every Copper Gasket Manufactured and Certified to International Standards
