The gasket of plate heat exchanger is a key component of plate heat exchanger, and its performance affects the overall efficiency of the heat exchanger. Its material, sealing performance, temperature resistance, corrosion resistance, compressibility and resilience, and dimensional accuracy affect the overall efficiency of the heat exchanger

1. Material Composition

The PTFE - rubber composite gasket represents a sophisticated combination of the remarkable properties inherent in polytetrafluoroethylene (PTFE) and rubber. PTFE, renowned for its outstanding chemical inertness and remarkable stability across an extensive temperature spectrum, exhibits an extremely low coefficient of friction and a high - degree of resistance to the vast majority of chemical substances. Complementarily, the rubber component imparts excellent elasticity and sealing capabilities, effectively compensating for the relatively limited elasticity of PTFE in isolation.

2. Sealing Performance

2.1 Sealing Mechanism

The composite structure of the gasket enables it to conform precisely to the minute irregularities present on the surfaces of plate heat exchangers. The rubber portion is adept at filling micro - gaps, while the PTFE layer furnishes a stable and chemically - resistant sealing interface. This synergy between the two materials ensures a comprehensive and reliable seal.

2.2 Leakage Resistance

Owing to the integration of materials, the PTFE - rubber composite gasket can effectively preclude fluid leakage. The PTFE surface, with its high resistance to chemical attack and abrasion, plays a pivotal role in maintaining the integrity of the seal over an extended service life. Simultaneously, the rubber layer provides the requisite compression and recovery capabilities, guaranteeing a tight seal even in the face of fluctuating pressures and temperatures.

3. Temperature Resistance

3.1 Broad Temperature Range

PTFE - rubber composite gaskets are engineered to endure a broad temperature range. PTFE itself can function across a temperature span from approximately - 200°C to around 260°C. The rubber component, with its own specific temperature tolerance, in conjunction with PTFE, enables the gasket to operate optimally in diverse industrial temperature environments.

3.2 Thermal Stability

At elevated temperatures, PTFE demonstrates remarkable resistance to softening and degradation. This property, combined with the rubber's ability to retain a certain degree of flexibility, ensures that the gasket can uphold its sealing performance without compromising its shape or integrity during thermal cycling. This thermal stability is crucial for the long - term reliability of plate heat exchangers.

4. Corrosion Resistance

4.1 Chemical Inertness of PTFE

PTFE is highly impervious to a wide array of chemicals, including strong acids, alkalis, and organic solvents. The PTFE layer within the composite gasket serves as a robust barrier against corrosive substances, safeguarding the gasket from chemical degradation.

4.2 Synergistic Protective Effect

Although the rubber part is not as chemically inert as PTFE, it is shielded by the PTFE layer. This synergistic effect renders the gasket eminently suitable for applications in corrosive media, such as in chemical processing plants. Here, it can resist the corrosive impacts of various chemical mixtures and consistently maintain its sealing function.

5. Compressibility and Resilience

5.1 Compressibility

The rubber component within the composite gasket endows it with excellent compressibility. When the plates of the heat exchanger are tightened, the gasket can be readily compressed to fill the gaps between the plates, ensuring a secure seal. The PTFE layer, despite its relative rigidity compared to rubber, also possesses a certain degree of flexibility, allowing it to adapt to compression without fracturing.

5.2 Resilience

Upon the release of pressure, the rubber part of the gasket, due to its inherent elasticity, recovers its original shape. This resilience property is of utmost importance for maintaining the seal during repeated cycles of compression and decompression, which are common in the operation of plate heat exchangers experiencing pressure fluctuations.

6. Dimensional Accuracy

6.1 Precision Manufacturing

These gaskets are typically fabricated using high - precision molds, ensuring consistent and accurate dimensions. The precise sizing of the gasket is fundamental to its proper installation and optimal sealing performance within the plate heat exchanger.

6.2 Dimensional Stability

PTFE - rubber composite materials exhibit commendable dimensional stability. They experience minimal expansion or contraction under normal operating conditions, which is essential for maintaining a precise fit between the gasket and the heat exchanger plates. This dimensional accuracy is critical for preventing leakage and ensuring the efficient operation of the heat exchanger.