High-Temperature Graphite Rupture Disc
Product Model: ZD-G05 (HT Graphite Grade)
Material: Special grade of impervious graphite formulated for sustained high-temperature operation.
Temperature Range: Suitable for continuous service up to 400°C in inert or reducing atmospheres; specific grades can exceed 600°C.
Key Feature: Maintains mechanical strength and corrosion resistance at elevated temperatures where metals creep and polymers degrade.
Primary Use: Venting of high-temperature process vessels, molten salt systems, pyrolysis units, and exhaust gas treatment in corrosive, hot environments.
Overview
Many high-temperature processes also involve corrosive atmospheres, creating a dual challenge for safety devices. Metals may suffer from creep or excessive corrosion, while polymers simply cannot survive. High-temperature graphite rupture discs are specifically engineered for this niche. Made from grades of graphite with enhanced thermal stability and oxidation resistance, they provide reliable overpressure protection in hot, chemically aggressive environments such as chemical vapor deposition (CVD), incineration off-gas lines, or high-temperature synthesis reactors where few other materials can perform.
Features & Benefits
Exceptional Thermal Stability: Retains dimensional stability and burst strength at temperatures that would cause most plastics and elastomers to fail and metals to weaken.
Corrosion Resistance at Temperature: Maintains its inertness to many acids, halogens, and molten salts even at elevated temperatures.
No Cooling Required: Can often be installed directly on hot vessels without the need for complex cooling jackets required for metal seals in some services.
Resistance to Thermal Shock: Graphite's properties allow it to withstand rapid temperature changes better than many ceramics.
How It Works
The operating principle remains tensile or scored fracture. The critical engineering lies in the material's ability to maintain its designed burst pressure accurately after prolonged exposure to high heat. Special graphites with lower permeability and modified binders are used to minimize oxidation and gas permeation, which could affect performance over time.
Specifications (Descriptive)
Available in sizes from DN50 to DN250. Standard high-temperature grades are rated for 400°C in air. For inert or reducing atmospheres (e.g., nitrogen, hydrogen, argon), service up to 600°C or higher is possible with specialized grades. Burst pressures are typically in the low to medium range (0.5 - 5 barg) due to material constraints at temperature. Holders must be designed with similar temperature capabilities, often using high-temperature alloys and special gasket materials like flexible graphite.
Q&A
Q: What is the main enemy of graphite at high temperature?
A: Oxidation. In air, graphite will slowly oxidize above about 350°C. For long-term service in oxidizing atmospheres above this temperature, a protective coating or a different material should be considered. Our HT grades have improved oxidation resistance.
Q: Can these discs handle thermal cycling?
A: Yes, graphite has good thermal shock resistance. However, the mechanical assembly (holder, bolts, gasket) must also be designed for the same thermal cycling to avoid leaks due to differential expansion.
Q: How is the burst pressure certified for high temperature?
A: The disc is rated based on its room-temperature burst pressure and a characterized derating factor for elevated temperature. Material properties are tested at temperature to establish this correlation. For critical applications, consulting with our engineers is essential.
About ZD Safety
We provide safety solutions for extreme environments. Our high-temperature graphite discs ensure that protection is not compromised by heat, enabling safe operation in some of the most thermally demanding processes across advanced industries.
