A hub guide to the main types of heat exchangers — gasketed plate, brazed plate, fully welded plate, plate-and-block, shell-and-tube, finned-tube and more — with selection guidance by construction, flow arrangement and industry application.
How heat exchangers are classified
Heat exchangers are classified in three overlapping ways: by construction (how the heat-transfer surface is built — plates, tubes, coils, fins), by flow arrangement (counter-current, co-current, cross-flow, or multi-pass) and by service (liquid-to-liquid, gas-to-liquid, condenser, evaporator, reboiler, air-cooler). This guide walks through the main construction types you will meet in industrial, HVAC and marine practice and links to detailed pages for each family.
Gasketed plate heat exchanger (plate and frame)
A stack of thin corrugated stainless-steel plates compressed between a fixed and movable cover, sealed by elastomer gaskets. Delivers the highest U-value per unit volume (4,000–7,000 W/m²·K on water) and is fully openable for cleaning. The workhorse of HVAC, district heating, chemical, food, marine oil coolers and general industrial duties below ~25 bar and ~180 °C. See our dedicated Plate and Frame Heat Exchanger Guide for construction detail and selection criteria.
Brazed plate heat exchanger
Same corrugated plates as a gasketed unit but vacuum-brazed together with copper or nickel — no gaskets, no frame. Very compact and inexpensive for small, clean, sealed duties: heat pumps, boiler heat interface units, oil coolers, refrigerant condensers and evaporators. Not openable, so unsuitable for fouling or serviced duties. Pressure ratings up to 45 bar; temperatures up to 200 °C with copper braze, 400 °C with nickel.
Fully welded plate heat exchanger
Plates laser-welded together in pairs (or in a full block) with no gaskets in the wetted path. Combines the compactness of a plate exchanger with the media compatibility of a shell-and-tube unit — handles hydrocarbons, refrigerants, steam and aggressive chemicals up to ~40 bar and ~350 °C. Used in petrochemical, refinery and chemical duties where gasket compatibility or leakage risk rules out a gasketed unit.
Welded plate-and-block heat exchanger
A fully welded plate pack contained in a rectangular block frame with removable side panels, so each of the four sides can be opened for inspection and mechanical cleaning. Bridges the gap between shell-and-tube (fully openable, high-pressure) and plate (compact, efficient) — chosen for fouling hydrocarbon duties, sulphuric acid coolers and other services where periodic cleaning is essential but gaskets are not acceptable.
Shell-and-tube heat exchanger
The oldest and most robust construction — a bundle of tubes inside a cylindrical shell, one fluid on the tube side, the other on the shell side. Handles the widest range of pressures (to 400+ bar), temperatures (cryogenic to 600+ °C), fluids (liquids, gases, two-phase) and fouling levels. Configurations follow the TEMA standard (BEM, AES, NEN, BKU, etc.) and are chosen for high-pressure duties, condensers, reboilers, marine seawater coolers and any service where a plate exchanger will not qualify.
Finned-tube and air-cooled heat exchanger
A tube bundle with extended aluminium or steel fins on the air side, cooled by forced or induced-draft fans. Used wherever a process fluid must be cooled but a reliable water supply is not available — refinery product coolers, gas compressor after-coolers, refrigeration condensers, HVAC coils. Also used inside as unit heaters and dry coolers.
Double-pipe and coil heat exchangers
Double-pipe (hairpin) exchangers use a pipe inside a pipe — simple, robust, and easy to serialise for very high pressures or small duties. Coil-in-tank and jacketed-vessel exchangers heat or cool the contents of a storage tank or reactor. Common in small chemical batch plants, pilot plants and utility skids.
How to choose the right type for your duty
Start with three questions: (1) What are the design pressure and temperature? — this rules out plate types above their limits and pushes you to fully welded or shell-and-tube. (2) How aggressive or fouling is the fluid? — gasketed plate for clean water and mild chemicals, welded plate or plate-and-block for hydrocarbons, shell-and-tube for seawater or heavy fouling. (3) Is space or serviceability more valuable? — plate exchangers save 60–80% of the footprint of an equivalent shell-and-tube. Then confirm materials, gasket compatibility, code stamp (ASME, PED, TEMA) and cleaning strategy. Our engineering team is happy to run a comparative selection — contact Blair at blair@shheatex.com or WhatsApp +86 133 1175 6331.
References & further reading
- Heat exchanger — Wikipedia
- Plate heat exchanger — Wikipedia
- Shell and tube heat exchanger — Wikipedia
Frequently asked questions
What are the main types of heat exchangers?
The main types by construction are gasketed plate (plate and frame), brazed plate, fully welded plate, welded plate-and-block, shell-and-tube, finned-tube/air-cooled, double-pipe (hairpin) and coil/jacketed exchangers. Plate types are the most compact and efficient for liquid-to-liquid duties; shell-and-tube handles the widest range of pressures, temperatures and fluids.
Which type of heat exchanger is most efficient?
Gasketed plate heat exchangers give the highest overall heat-transfer coefficient per unit area (4,000–7,000 W/m²·K on water) — three to five times higher than a shell-and-tube unit for the same duty. That is why plate exchangers dominate HVAC, district heating and general water-to-water applications where their pressure and temperature limits are acceptable.
When should I choose shell-and-tube over a plate heat exchanger?
Choose shell-and-tube when the design pressure exceeds ~25 bar (plate limit), the temperature exceeds ~180 °C for gasketed units, the fluid is heavily fouling and needs mechanical tube cleaning, the service is a condenser or reboiler with two-phase flow, or a class-society or licensor specification calls for it (e.g. marine seawater coolers, refinery duties).
What is the difference between plate and frame and fully welded plate heat exchangers?
A plate and frame exchanger has gaskets between the plates and is fully openable for cleaning. A fully welded plate exchanger has the plates laser-welded together — no gaskets in the wetted path — so it handles hydrocarbons, refrigerants and higher pressures/temperatures, but cannot be opened. A welded plate-and-block unit adds removable side panels so the plate pack can still be inspected and cleaned.
Send your working conditions to Blair
Share your medium, temperatures, flow rate and pressure — Blair will return a thermal selection and indicative pricing after reviewing the available data.