As important equipment for storing and transporting high-pressure media, the sealing structure design of pressure vessels directly affects operational safety and reliability. A good sealing design not only prevents media leakage and ensures system pressure stability but also effectively extends the service life of the equipment. FRHE will analyze the key design considerations for pressure vessel sealing structures from three aspects: structure, materials, and operating conditions.

The selection of the sealing structure type is the primary step in the design process. Common sealing structures include flange seals, threaded seals, welded seals, and gasket seals. Flange connections are suitable for detachable parts, facilitating maintenance and replacement; welded seals are suitable for high-pressure or high-temperature applications, ensuring permanent sealing; while gasket seals are widely used in medium- and low-pressure equipment. During the design phase, the sealing method should be rationally selected based on the characteristics of the medium, pressure rating, and temperature range to achieve the best sealing effect.

The selection of sealing materials significantly affects sealing performance. Commonly used sealing materials include rubber, polytetrafluoroethylene (PTFE), graphite, and metal ring gaskets. Rubber materials are suitable for medium- and low-temperature, non-corrosive media; graphite and metal gaskets can withstand high-temperature and high-pressure environments and possess excellent chemical stability. During the design phase, the corrosiveness of the medium, temperature changes, and pressure fluctuations should be comprehensively considered to select materials that meet sealing requirements and possess durability.

The design of the sealing surface structure is also crucial to ensuring sealing reliability. The sealing surface should maintain good flatness and smoothness, avoiding scratches or pits. For high-pressure vessels, concave-convex surfaces, ring joints, or lens surfaces are typically used to improve the sealing specific pressure and prevent leakage. Simultaneously, the bolt preload should be evenly distributed to prevent uneven stress on the sealing surface, which could lead to deformation.

Temperature and stress factors must be fully considered during the design phase. Temperature fluctuations cause thermal expansion and contraction of materials, affecting the sealing clearance; while internal pressure changes may lead to stress concentration in the structure. Through reasonable structural compensation design and stress analysis, the risk of seal failure can be effectively reduced.

The sealing structure design of pressure vessels requires comprehensive consideration of structural form, material properties, sealing surface precision, and operating conditions. Only by fully optimizing these factors during the design phase can long-term, safe, and reliable sealing performance be ensured under high-pressure environments.