How to ensure long-term sealing and structural integrity ofsteel sheet pressure plate pressure cover under high-temperature or corrosive conditions?
Publish Time: 2026-01-22
As critical connection and sealing components, steel sheet pressure plate pressure cover often need to serve in harsh environments such as high temperature, high humidity, strong acids and alkalis, or salt spray for extended periods. Their core mission is not only to withstand mechanical loads but also to maintain reliable sealing performance, preventing media leakage, structural corrosion, and even safety accidents. Ensuring the long-term sealing and structural integrity of steel sheet pressure plates and pressure covers under extreme conditions has become a key issue in engineering design and material application.1. Material Selection: Resisting Environmental Corrosion from the SourceFaced with the dual challenges of high temperature and corrosion, materials are the first line of defense. While ordinary carbon steel is inexpensive, it is prone to oxidation and decarburization above 300℃ and corrodes rapidly in environments containing sulfur and chloride ions. Therefore, high-end applications generally use heat-resistant alloy steel or stainless steel. For example, 304/316L stainless steel, thanks to its chromium-nickel passivation film, exhibits excellent corrosion resistance in most acidic, alkaline, and marine environments. For higher temperature applications, heat-resistant steels containing molybdenum and niobium, or nickel-based alloys, are selected, offering not only strong oxidation resistance but also maintaining high strength at high temperatures. Furthermore, some applications utilize composite structures—a high-strength carbon steel base provides support, while the surface is overlaid with or coated with corrosion-resistant alloys, balancing performance and economy.2. Surface Protection: Constructing a Multi-Barrier SystemEven with high-quality materials, advanced surface treatment technologies are still necessary to extend service life. Dacromet coatings, due to their lack of hydrogen embrittlement, high salt spray resistance, and good heat resistance, are widely used for corrosion protection of pressure plates and glands. Hot-dip galvanizing is suitable for moderately corrosive environments, but the zinc layer is prone to oxidation and failure at high temperatures. In combined high-corrosion and high-temperature conditions, ceramic coatings or aluminizing treatments can form a dense, high-melting-point protective layer. It is important to note that all coatings must cover areas outside the sealing contact surface to avoid affecting the fit accuracy of metal-to-metal or metal-to-seal rings.3. Sealing Structure Design: Adapting to Thermal Deformation and Chemical CompatibilityHigh temperatures cause metal expansion, and corrosion can erode the microstructure of the sealing surface, making traditional rigid seals prone to failure. Therefore, modern gland plates often employ elastic compensation and multiple sealing mechanisms. For example, metal spiral wound gaskets or bellows-type sealing rings are embedded in the gland's sealing groove; their flexible structure can absorb displacement caused by thermal expansion and contraction. For flange connections, tongue and groove designs are used to laterally restrain the gasket and prevent it from being blown out. Simultaneously, the sealing material must be compatible with the medium and temperature—graphite gaskets are stable at high temperatures, while fluororubber is superior to ordinary rubber in highly corrosive environments.4. Tightening and Stress Control: Preventing Loosening and Localized FailureHigh-temperature creep and vibration can easily lead to a decrease in bolt preload, which in turn can cause gland loosening and seal failure. Solutions include: using high-temperature anti-loosening nuts, disc spring washers to provide continuous elasticity compensation, or using hydraulic tensioners to precisely control the preload. Furthermore, the thickness and reinforcing rib layout of the pressure plate and pressure cover are optimized through finite element analysis to ensure that the deformation of the sealing surface is controlled within the micrometer level under the combined effects of thermal stress and internal pressure, maintaining uniform clamping force.The reliability of the steel sheet pressure plate pressure cover under extreme conditions cannot be guaranteed by a single technology, but rather by a systematic integration of materials science, surface engineering, sealing mechanics, and precision manufacturing. From the precise selection of corrosion-resistant alloys to the innovative design of intelligent sealing structures, and the strict control of assembly processes, every step is crucial to the safety boundaries and service life of the equipment. In the future, with the integration of intelligent coatings, self-healing materials, and digital twin monitoring technology, the pressure plate and pressure cover will not only withstand harsh environments but also be able to sense and warn of potential risks, truly achieving a leap from passive protection to proactive safeguarding.
