Selecting the correct gasket material for a plate heat exchanger (PHE) is essential for system reliability. Gaskets serve as the primary seal between heat transfer plates; if the material is incompatible with the process fluid, temperature, or pressure, leaks and premature failure will follow.

First, consider temperature range. Standard EPDM (Ethylene Propylene Diene Monomer) performs well from -40°C to +150°C, making it suitable for hot water, steam, and many food applications. However, EPDM is incompatible with oils, hydrocarbons, and solvents, which cause rapid swelling or shrinkage.

NBR (Nitrile Butadiene Rubber) is the choice for oil-based fluids. It resists mineral oils, grease, and diesel at temperatures up to +130°C. Avoid NBR in hot water above +120°C or with strong acids, as degradation accelerates.

Viton (FKM) excels in aggressive chemical environments, handling acids, fuels, and high temperatures up to +200°C. Its cost is higher, but the extended service life justifies the investment for demanding processes.

Pressure also dictates gasket hardness. Low-pressure applications (below 10 bar) can use softer Shore A 70-80 materials for better compression. For high-pressure systems (above 16 bar), harder grades (Shore A 85-90) resist extrusion.

Chemical compatibility must be verified using published resistance charts. Always test a sample with the actual process fluid at operating temperature for at least 48 hours. Measure dimensional change, hardness variation, and weight gain.

Installation quality matters equally. Ensure gasket grooves are clean, and apply adhesive only if required by the manufacturer. Avoid over-tightening, which crushes the gasket and reduces elasticity.

In summary, match gasket material to fluid type, stay within temperature limits, and confirm pressure ratings. A bad gasket choice can shut down production; a correct one ensures years of trouble-free heat transfer.