The working principle of bursting disc is based on the precise control of the mechanical properties of the material. The working conditions of different industries have put forward differentiated requirements for bursting disc materials. For example, the petrochemical industry often faces corrosive media and high temperature environments, while the food processing industry has strict requirements for the hygiene and safety of materials, which determines that bursting disc must choose suitable metal or non-metallic materials. Taking metal materials as an example, commonly used stainless steel, hastelloy and other materials, their tensile strength, yield limit and other mechanical parameters will be accurately tested in the laboratory, and the production enterprise will determine the optimal thickness of the material through formula calculation based on the design burst pressure provided by the buyer. When the pressure in the equipment reaches a preset value, the stress on the material will just exceed its own tensile strength, thereby achieving instantaneous rupture. On the other hand, non-metallic materials such as polytetrafluoroethylene, although their tensile strength is lower than that of metals, have irreplaceable advantages in the scene of highly corrosive media. Its working principle is also based on the stress limit of the material itself. By controlling the thickness and molding process, the bursting disc can be accurately broken under the set pressure, while avoiding early failure due to medium corrosion.
Structural design is another element of bursting disc to achieve precise work. There are obvious differences in the rupture mechanism and applicable scenarios of bursting disc of different structural types. Positive arch type bursting disc is currently one of the most widely used types. Its structure is an upward raised arc. When working, the internal pressure of the equipment acts on the inside of the arch, causing the arch surface to produce tensile stress. When the pressure reaches the design value, the arch surface is stretched and ruptured because the stress exceeds the material limit, forming a relief channel. The advantage of this structure is that the discharge area is the same as the equipment interface area, the discharge efficiency is high, and it is suitable for most low- to medium-pressure working conditions. The reverse arch type bursting disc is the opposite. Its arch surface faces the outside of the pressure source. When working, the pressure acts on the outside of the arch, causing the arch surface to produce compressive stress. When the pressure reaches a preset value, the arch surface will suddenly stabilize and flip, and at the same time break along the prefabricated weak link to achieve pressure relief. The advantage of the anti-arch structure is that it has strong fatigue resistance and can withstand multiple pressure fluctuations without early failure. Therefore, it is widely used in working conditions with frequent pressure changes. In addition, the flat-plate bursting disc has a simple structure. By setting a weak groove in the center of the flat plate, it can be accurately broken along the weak groove when it breaks. It is suitable for scenes of low-pressure and low-viscosity media.
In addition to material and structure, the working principle of bursting disc also involves the mutual cooperation of pressure transfer and discharge control. In practical applications, bursting disc does not work independently, but forms a complete safety system together with equipment and discharge pipes. When the pressure in the equipment rises abnormally, the pressure will be quickly transmitted through the medium to the surface of the bursting disc. Since the interface between the bursting disc and the equipment is connected by sealed welding or flange, the pressure is transmitted to the bursting disc material itself without loss. This process requires that the sealing at the interface must be reliable. If there is leakage, it will cause a delay in pressure transfer, which may make the bursting disc unable to respond to the overpressure situation in time. When the bursting disc breaks, the high-pressure medium will be transported to a safe area through the discharge pipe. At this time, the diameter, length and other parameters of the discharge pipe need to match the discharge capacity of the bursting disc. If the diameter of the pipeline is too small, it will cause the discharge resistance to increase, and the pressure in the equipment cannot be quickly reduced, and the protective effect will be lost. If the length of the pipeline is too long, the discharge efficiency may decrease due to pressure loss during the flow of the medium. Therefore, in the working system of bursting disc, the timeliness of pressure transfer and the smoothness of the discharge channel are important guarantees for the effective implementation of the principle of bursting disc. This also requires buyers not only to pay attention to the bursting disc itself when selecting the model, but also to consider it comprehensively in combination with the design parameters of the entire system.
