Plate efficiency at pressures a gasket cannot take.

The plate pack is fully welded.

The shell provides pressure containment.

Neither a gasketed unit nor a tube bundle does both.

It occupies the space between them.

High pressure and steam duties are typical.

Far smaller and lighter for the same duty.

Plate surface transfers more per unit volume.

Closer temperature approaches are achievable.

Plant room space and floor loading often decide.

Shell-and-tube remains easier to clean mechanically.

The trade is size against access.

The plate side, wherever there is a choice.

It is the harder side to clean.

The shell side is generally more accessible.

Getting this backwards is difficult to undo.

Decide it during design, not commissioning.

Filtration upstream helps either way.

Chemically, in place, as the normal regime.

The welded pack has no mechanical access.

Cleaning connections should be designed in.

Shell side access varies by design.

Ask what is removable before ordering.

Plan the cleaning method with the selection.

Generally not, and that is the main exclusion.

Narrow plate channels trap solids.

No mechanical cleaning is available to recover them.

Spiral geometry suits slurries instead.

Gasketed units suit moderate fouling.

Match the construction to the fluid.

High pressure refrigeration circuits.

Steam heating and condensing duties.

District heating substations.

Process applications with demanding conditions.

Anywhere space and weight are constrained.

Clean fluids on the plate side throughout.

Design pressure and temperature on both sides.

Both fluids and their material compatibility.

Flow rates and required approach.

Fouling expectations and cleaning intent.

Applicable pressure vessel code.

Available space and lifting access.