In shell-and-tube thermal process equipment, the tubesheet is a core load-bearing component integrating positioning, fixing, pressure isolation and sealing partition. As the main force-bearing end plate of the equipment, it does not participate in heat exchange, but undertakes structural stability and medium partition tasks. It completely separates tube-side and shell-side media to prevent fluid mixing, leakage and structural failure, and is widely used in industrial temperature control, waste heat recovery, chemical refrigeration and other harsh working systems.

The tubesheet is a thick precision perforated metal plate with uniformly arranged standard tube holes. All heat transfer tubes penetrate the holes and are firmly fixed, realizing accurate positioning and stable support for the entire tube bundle. It standardizes the spacing of tube bundles, avoids tube shaking, offset and resonance wear caused by fluid scouring during operation, eliminates heat transfer disorder caused by loose tube bundles under large-flow conditions, and maintains long-term structural stability of internal heat exchange components.

Medium isolation and high-pressure sealing are the core functional values of tubesheets. The component strictly divides the equipment interior into two independent closed cavities: tube side and shell side, ensuring two media with different temperatures and properties flow separately without interference. The joints between tube holes and tube walls are reinforced and sealed by expansion welding, fusion welding or composite processing, resisting high temperature, high pressure and alternating thermal impact. It effectively prevents cross-region leakage and medium cross-contamination, meeting sealing requirements for high-risk working conditions such as corrosive chemical fluids, high-pressure refrigerants and high-temperature heat transfer media.

According to structural differences and process standards, mainstream tubesheet types include fixed, floating and detachable structures. Fixed tubesheets feature high overall rigidity, excellent pressure resistance and simple durable structure, suitable for stable working conditions with high temperature, high pressure and clean media. Floating tubesheets can expand and contract freely with temperature changes, offset thermal deformation stress and avoid weld cracking under large temperature difference conditions. Detachable tubesheets facilitate tube bundle disassembly, cleaning and maintenance, adapting to fluid environments prone to scaling and impurity accumulation.

Material selection and machining accuracy determine the service life and working condition adaptability of tubesheets. Carbon steel is applied for conventional clean water and oil working conditions with high mechanical strength and cost performance. Stainless steel is used for seawater, salt fog and mild acid-base environments with excellent pitting and intergranular corrosion resistance. Special alloy forgings are adopted for heavy corrosion and ultra-high pressure scenarios in fine chemical and oil-gas industries. Ultra-precise tolerances of hole diameter, pitch and flatness ensure tube bundle verticality and tightness, reducing equipment failure risks fundamentally.

As the core pressure-bearing terminal of thermal equipment, the tubesheet acts as a structural barrier for operational stability and medium safety. Reasonable material selection, precise perforation technology and optimized structural matching effectively improve pressure resistance, eliminate medium mixing and reduce thermal stress loss, serving as a key guarantee for safe, long-term and low-fault operation of industrial thermal systems.