In plate-type heat exchangers used in chemical process industries, what is the typical thickness range (in millimetres) for the single-piece pressed heat-transfer plates that have grooves and corrugations for turbulence and strength?

Introduction / Context:
Plate-type heat exchangers are widely used for liquid–liquid and liquid–two-phase services because their corrugated plates create high turbulence, large heat-transfer coefficients, and compact footprints. An important specification is the thickness of the heat-transfer plates, which must balance mechanical strength, corrosion allowance, and thermal performance.

Given Data / Assumptions:

• The plates are single-piece pressings with grooves and corrugations.
• Material is typically stainless steel, titanium, or other corrosion-resistant alloys.
• Application is general process duty (not extreme pressure/erosion cases).

Concept / Approach:
Thinner plates reduce thermal resistance and improve overall heat-transfer coefficient U, but too-thin plates may deform under pressure or corrode quickly. Industry practice selects a moderate thickness that supports gasket compression and resists fatigue from flow-induced vibrations.

Step-by-Step Solution:

Verification / Alternative check:
Typical vendor datasheets list plate thicknesses around 0.4, 0.5, 0.6, and 0.7 mm for stainless steels, with heavier plates used only for special duties. This aligns with a 0.3–0.8 mm band for most services.

Why Other Options Are Wrong:

• 1.25 to 3.125 mm: Excessively thick for standard plate exchangers; would degrade heat transfer and add cost.
• 3.5 to 7.0 mm and 8 to 12 mm: Typical of pressure-retaining shells or tube sheets, not thin transfer plates.
• 0.05 to 0.1 mm: Too thin to maintain integrity and gasket sealing under operating pressures.

Common Pitfalls:
Confusing plate thickness with frame/cover plate thickness; overlooking that higher corrosion allowance is usually handled by material selection rather than drastic thickness increases.

Final Answer:
0.3 to 0.8 mm