A bursting disc (bursting membrane) is an overpressure protection device used in pressure vessels or pipelines. Its core function is to precisely rupture at a set pressure to release pressure. The requirements for metal materials need to comprehensively consider their mechanical properties, chemical stability, corrosion resistance and adaptability to the working environment. The following are the main requirements of bursting discs for metal materials:
1. Mechanical performance requirements
Strength and ductility balance
The metal must have sufficient tensile strength and yield strength to withstand normal working pressure, and at the same time, it must have a certain ductility (plastic deformation ability) to avoid premature failure or inaccurate rupture pressure due to brittle fracture.
Accurate bursting pressure
The material must ensure uniform rupture at the set pressure, so the material must be uniform, free of internal defects (such as pores, inclusions), and stable performance between batches.
2. Corrosion resistance
Media compatibility
The metal must be able to resist corrosion from the working medium (such as acid, alkali, gas, liquid). For example:
Strongly corrosive environment: choose Hastelloy, titanium (Ti) or tantalum (Ta).
General corrosive environment: 316L stainless steel, nickel-based alloy (such as Inconel).
Surface treatment
If the medium is highly corrosive, the metal may need to be plated (such as nickel plating, gold plating) or passivated.
3. Temperature stability
High temperature environment
The material needs to maintain strength at high temperatures and avoid creep or oxidation (such as nickel-based alloys, titanium alloys).
Low temperature environment
Low temperature brittleness should be avoided (such as austenitic stainless steel performs better at low temperatures).
4. Fatigue resistance
- If the system pressure fluctuates frequently (such as pulse pressure), the material needs to have good fatigue resistance to prevent microcrack propagation due to cyclic loads.
5. Processing performance
Formability
Bursting discs are usually thin sheet structures, and the material needs to be easy to stamp, stretch or weld (such as stainless steel, aluminum).
Thickness uniformity
The thickness tolerance must be kept tight during the manufacturing process to ensure the accuracy of the burst pressure.
6. Economy and substitutability
- Under the premise of meeting the performance requirements, give priority to low-cost and easily available materials (such as 304/316 stainless steel).
- Precious metals (such as tantalum) may be required under special conditions, and the cost and necessity must be weighed at this time.
Related standards
ASME BPVC Section VIII: Specifies the selection and design standards for bursting disc materials.
API 520/526: Bursting disc materials and installation requirements for the petrochemical industry.
ISO 4126: Test methods for bursting disc material properties in international standards.
Summary
The selection of bursting disc metal materials needs to be comprehensively evaluated based on specific working conditions (pressure, temperature, medium), economy and manufacturing process. The core is to ensure that the material can rupture reliably at the set pressure and withstand environmental conditions stably for a long time. Customized materials or composite structures (such as metal + coating) may be required under special conditions.