Graphite Insulation Ring And Graphite Seal Ring For Vacuum Furnace

Graphite Insulation Ring and Seal Ring for Vacuum Furnace

Product Overview

Our graphite rings and seal rings are precision-machined annular components used in vacuum furnaces for thermal insulation, gas sealing, and hearth support. Manufactured from high-purity isostatic and extruded graphite, these rings maintain dimensional stability and mechanical strength at temperatures up to 2500°C in vacuum or inert gas environments. They serve as insulation layers between hot zones and water-cooled furnace walls, support graphite heating elements, and restrict radiative heat loss in high-temperature furnace designs.

Graphite rings are critical consumable components in vacuum brazing, sintering, and graphitization furnaces. Over repeated thermal cycles, rings can warp, crack, or wear at sealing surfaces. At Jincheng Graphite, we manufacture graphite insulation rings, seal rings, support rings, and bayonet rings in both standard and custom dimensions, with inner diameters from 50 mm to over 1000 mm. Each ring is precision-turned to maintain concentricity and flatness for reliable furnace performance.

Key Features

• High temperature stability - maintains strength and shape up to 2500°C
• Precision machined - concentric, flat rings with tight dimensional tolerances
• Low thermal conductivity - graphite felt and rigid rings minimize heat loss
• Thermal shock resistant - withstands rapid heating and cooling cycles
• Custom sizes - ID from 50 mm to 1000+ mm, wall thickness per requirement
• Multiple grades - high-density structural rings or low-density insulation rings
• Long service life - resists oxidation and mechanical fatigue over many cycles
• Bayonet and groove designs - interlocking ring configurations for sealed hot zones

Technical Specifications

Applications

• Vacuum brazing furnaces - insulation and seal rings between hot zone and wall
• Vacuum sintering furnaces - support rings for hearth and heating elements
• Graphitization furnaces - thermal insulation rings at extreme temperatures
• CVD furnaces - gas distribution and shield rings in reaction chambers
• Crystal growth furnaces - support and insulation rings in crystal pullers
• Heat treatment furnaces - baffle and restriction rings for temperature uniformity

Why Choose Jincheng Graphite?

• Precision turning capability - large diameter ring machining up to 1200 mm
• Multiple density options - choose structural or insulating density for your needs
• Custom ring geometries - bayonet, groove, tongue-and-groove, and stepped rings
• Reverse engineering - we replicate worn rings from samples or drawings
• Fast lead times - standard rings ship within 7-10 days
• Competitive pricing - factory-direct precision-machined graphite rings
• Refurbishment service - re-machine worn ring surfaces to extend life
• Global export - shipping to furnace builders and maintenance teams worldwide

FAQ

Q: Can you manufacture large-diameter rings for our furnace?
A: Yes. We can turn graphite rings with inner diameters up to 1200 mm or larger by fabricating from multiple segments if needed. Send us your ring dimensions (ID, OD, height) and we will quote.

Q: What density should I choose for insulation vs. structural rings?
A: Low-density graphite (1.55-1.65 g/cm³) provides better thermal insulation but lower strength. High-density graphite (1.75-1.85 g/cm³) is used for structural support, seal surfaces, and load-bearing rings. Tell us your application and we will recommend the right grade.

Q: How do I order a replacement ring?
A: Send us a drawing or the exact inner diameter, outer diameter, and height, along with the material grade if known. If you have a worn ring sample, we can replicate it by measuring directly.

Q: Do rings need coating for vacuum furnace use?
A: Most vacuum furnace rings use uncoated graphite. If your process involves oxidizing or corrosive atmospheres, we can offer CVD SiC-coated rings for extended service life.